\u00a9 2023 The Author(s), under exclusive license to Springer Nature Switzerland AG.
\n\nWe are grateful to Phani Motamarri for sharing the unpublished results shown in Table 12.1. We acknowledge the help of Arpit Bhardwaj, Sambit Das and Xin Jing in running some of the DFT-FE and SQ simulations, and generating the corresponding figures. KB, MO and MP acknowledge the support of the Army Research Laboratory under Cooperative Agreement Number W911NF-12-2-0022. VG acknowledges the support of the U.S. Department of Energy, Office of Science through grants DE-SC0008637 and DE-SC0017380. VG also gratefully acknowledges the support of the Army Research Office through the DURIP grant W911NF1810242. PS acknowledges support of the U.S. Department of Energy, Office of Science through grant DE-SC0019410. The computations presented here were conducted on the Resnick High Performance Cluster at Caltech, the Great Lakes High Performance Cluster at the University of Michigan, the Oak Ridge Leadership Computing Facility, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory under contract DE-AC05-00OR22725, and the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Laboratory, Department of Energy, or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.
", "abstract": "This chapter presents controlled approximations of Kohn\u2013Sham density functional theory (DFT) that enable very large scale simulations. The work is motivated by the study of defects in crystalline solids, though the ideas can be used in other applications. The key idea is to formulate DFT as a minimization problem over the density operator, and to cast spatial and spectral discretization as systematically convergent approximations. This enables efficient and adaptive algorithms that solve the equations of DFT with no additional modeling, and up to desired accuracy, for very large systems, with linear and sublinear scaling. Various approaches based on such approximations are presented, and their numerical performance is demonstrated through selected examples. These examples also provide important insights into the mechanics and physics of defects in crystalline solids.
", "date": "2023-12-20", "date_type": "published", "publisher": "Springer", "place_of_pub": "Cham, Switzerland", "pagerange": "525-578", "isbn": "978-3-031-22339-6", "book_title": "Density Functional Theory: Modeling, Mathematical Analysis, Computational Methods, and Applications", "editors": { "items": [ { "id": "Canc\u00e8s-Eric", "name": { "family": "Canc\u00e8s", "given": "Eric" } }, { "id": "Friesecke-Gero", "name": { "family": "Friesecke", "given": "Gero" } } ] }, "official_url": "https://authors.library.caltech.edu/records/nc59f-2jz76", "funders": { "items": [ { "grant_number": "W911NF-12-2-0022" }, { "grant_number": "DE-SC0008637" }, { "grant_number": "DE-SC0017380" }, { "grant_number": "W911NF1810242" }, { "grant_number": "DE-SC0019410" }, { "grant_number": "DE-AC05-00OR22725" }, { "grant_number": "DE-AC02-05CH11231" } ] }, "local_group": { "items": [ { "id": "GALCIT" }, { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1007/978-3-031-22340-2_12", "pub_year": "2023", "author_list": "Bhattacharya, Kaushik; Gavini, Vikram; et al." }, { "id": "https://authors.library.caltech.edu/records/qw767-p4h24", "eprint_id": 117377, "eprint_status": "archive", "datestamp": "2023-08-20 06:09:13", "lastmod": "2023-10-24 22:30:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lin-Yiheng", "name": { "family": "Lin", "given": "Yiheng" }, "orcid": "0000-0001-6524-2877" }, { "id": "Hu-Yang", "name": { "family": "Hu", "given": "Yang" } }, { "id": "Shi-Guanya", "name": { "family": "Shi", "given": "Guanya" }, "orcid": "0000-0002-9075-3705" }, { "id": "Sun-Haoyuan", "name": { "family": "Sun", "given": "Haoyuan" }, "orcid": "0000-0002-6203-0198" }, { "id": "Qu-Guannan", "name": { "family": "Qu", "given": "Guannan" }, "orcid": "0000-0002-5466-3550" }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" }, "orcid": "0000-0002-5923-0199" } ] }, "title": "Perturbation-based Regret Analysis of Predictive Control in Linear Time Varying Systems", "ispublished": "unpub", "full_text_status": "public", "note": "Yiheng Lin, Yang Hu, Haoyuan Sun, Guanya Shi, and Guannan Qu contributed equally to this work. \n\nThis work was supported by NSF grants CNS-2106403, NGSDI-2105648, and AitF-1637598, with additional support from Amazon AWS, PIMCO, and the Resnick Sustainability Insitute. Yiheng Lin was supported by Kortschak Scholars program.", "abstract": "We study predictive control in a setting where the dynamics are time-varying and linear, and the costs are time-varying and well-conditioned. At each time step, the controller receives the exact predictions of costs, dynamics, and disturbances for the future k time steps. We show that when the prediction window k is sufficiently large, predictive control is input-to-state stable and achieves a dynamic regret of O(\u03bb^kT), where \u03bb < 1 is a positive constant. This is the first dynamic regret bound on the predictive control of linear time-varying systems. We also show a variation of predictive control obtains the first competitive bound for the control of linear time-varying systems: 1 + O(\u03bb^k). Our results are derived using a novel proof framework based on a perturbation bound that characterizes how a small change to the system parameters impacts the optimal trajectory.", "date": "2021-12", "date_type": "published", "publisher": "Advances in Neural Information Processing Systems", "pagerange": "1-12", "id_number": "CaltechAUTHORS:20221012-231545995", "isbn": "9781713845393", "book_title": "Advances in Neural Information Processing Systems 34 (NeurIPS 2021)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221012-231545995", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-2106403" }, { "agency": "NSF", "grant_number": "CNS-2105648" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "Amazon Web Services" }, { "agency": "PIMCO" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Kortschak Scholars Program" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "contributors": { "items": [ { "id": "Ranzato-M", "name": { "family": "Ranzato", "given": "M." } }, { "id": "Beygelzimer-A", "name": { "family": "Beygelzimer", "given": "A." } }, { "id": "Dauphin-Y", "name": { "family": "Dauphin", "given": "Y." } }, { "id": "Liang-P-S", "name": { "family": "Liang", "given": "P. S." } }, { "id": "Wortman-Vaughan-Jennifer", "name": { "family": "Wortman Vaughan", "given": "J." }, "orcid": "0000-0002-7807-2018" } ] }, "pub_year": "2021", "author_list": "Lin, Yiheng; Hu, Yang; et al." }, { "id": "https://authors.library.caltech.edu/records/wgtme-df518", "eprint_id": 111923, "eprint_status": "archive", "datestamp": "2023-08-20 03:51:43", "lastmod": "2026-03-29 14:43:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kulits-Peter", "name": { "family": "Kulits", "given": "Peter" } }, { "id": "Wall-Jake", "name": { "family": "Wall", "given": "Jake" } }, { "id": "Bedetti-Anka", "name": { "family": "Bedetti", "given": "Anka" } }, { "id": "Henley-Michelle-D", "name": { "family": "Henley", "given": "Michelle" }, "orcid": "0000-0002-1675-7388" }, { "id": "Beery-Sara", "name": { "family": "Beery", "given": "Sara" }, "orcid": "0000-0002-2544-1844" } ] }, "title": "ElephantBook: A Semi-Automated Human-in-the-Loop System for Elephant Re-Identification", "ispublished": "unpub", "full_text_status": "public", "keywords": "elephants, re-identification, conservation tech", "note": "\u00a9 2021 Copyright held by the owner/author(s). \n\nWe would like to thank the entire team at the Mara Elephant Project for their efforts in deploying this system. This work was supported, through funding, data storage, and computing resources, by Microsoft AI for Earth, the Caltech Resnick Sustainability Institute, and NSF GRFP Grant No. 1745301, the views are those of the authors and do not necessarily reflect the views of these organizations.\n\nPublished - 3460112.3471947.pdf
Accepted Version - 2106.15083.pdf
", "abstract": "African elephants are vital to their ecosystems, but their populations are threatened by a rise in human-elephant conflict and poaching. Monitoring population dynamics is essential in conservation efforts; however, tracking elephants is a difficult task, usually relying on the invasive and sometimes dangerous placement of GPS collars. Although there have been many recent successes in the use of computer vision techniques for automated identification of other species, identification of elephants is extremely difficult and typically requires expertise as well as familiarity with elephants in the population. We have built and deployed a web-based platform and database for human-in-the-loop re-identification of elephants combining manual attribute labeling and state-of-the-art computer vision algorithms, known as ElephantBook. Our system is currently in use at the Mara Elephant Project, helping monitor the protected and at-risk population of elephants in the Greater Maasai Mara ecosystem. ElephantBook makes elephant re-identification usable by non-experts and scalable for use by multiple conservation NGOs.", "date": "2021-06-28", "date_type": "published", "publisher": "Association for Computing Machinery", "place_of_pub": "New York, NY", "pagerange": "88-98", "id_number": "CaltechAUTHORS:20211117-175445588", "isbn": "978-1-4503-8453-7", "book_title": "ACM SIGCAS Conference on Computing and Sustainable Societies (COMPASS '21)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20211117-175445588", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Microsoft AI for Earth" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1745301" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1145/3460112.3471947", "primary_object": { "basename": "2106.15083.pdf", "url": "https://authors.library.caltech.edu/records/wgtme-df518/files/2106.15083.pdf" }, "related_objects": [ { "basename": "3460112.3471947.pdf", "url": "https://authors.library.caltech.edu/records/wgtme-df518/files/3460112.3471947.pdf" } ], "pub_year": "2021", "author_list": "Kulits, Peter; Wall, Jake; et al." }, { "id": "https://authors.library.caltech.edu/records/1fzny-bps82", "eprint_id": 109657, "eprint_status": "archive", "datestamp": "2023-08-20 03:47:55", "lastmod": "2026-03-29 21:45:26", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Werner-Lucien", "name": { "family": "Werner", "given": "Lucien" } }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Pricing flexibility of shiftable demand in electricity markets", "ispublished": "unpub", "full_text_status": "public", "keywords": "electricity markets, demand response, mechanism design, incentives,\nflexibility, shiftable demand", "note": "\u00a9 2021 Copyright held by the owner/author(s).\nThis work is licensed under a Creative Commons Attribution International 4.0 License.\n\nPublished: 22 June 2021.\n\nThis work was supported by VMWare and NSF Grants CNS-2105648,\nAitF-1637598, CNS-1518941, NSF ECCS 1931662, and by the Resnick\nSustainability Institute at Caltech. We thank the anonymous reviewers\nfor their careful reading of this paper and for their insightful\nsuggestions.\n\nPublished - 3447555.3464847.pdf
", "abstract": "Enabling participation of demand-side flexibility in electricity markets is key to improving power system resilience and increasing the penetration of renewable generation. In this work we are motivated by the curtailment of near-zero-marginal-cost renewable resources during periods of oversupply, a particularly important cause of inefficient generation dispatch. Focusing on shiftable load in a multi-interval economic dispatch setting, we show that incompatible incentives arise for loads in the standard market formulation. While the system's overall efficiency increases from dispatching flexible demand, the overall welfare of loads can decrease as a result of higher spot prices. We propose a market design to address this incentive issue. Specifically, by imposing a small number of additional constraints on the economic dispatch problem, we obtain a mechanism that guarantees individual rationality for all market participants while simultaneously obtaining a more efficient dispatch. Our formulation leads to a natural definition of a uniform, time-varying flexibility price that is paid to loads to incentivize flexible bidding. We provide theoretical guarantees and empirically validate our model with simulations on real-world generation data from California Independent System Operator (CAISO).", "date": "2021-06-22", "date_type": "published", "publisher": "Association for Computing Machinery", "place_of_pub": "New York, NY", "pagerange": "1-14", "id_number": "CaltechAUTHORS:20210629-211519470", "isbn": "978-1-4503-8333-2", "book_title": "e-Energy '21: Proceedings of the Twelfth ACM International Conference on Future Energy Systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210629-211519470", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "VMWare" }, { "agency": "NSF", "grant_number": "CNS-2105648" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "CNS-1518941" }, { "agency": "NSF", "grant_number": "ECCS-1931662" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1145/3447555.3464847", "primary_object": { "basename": "3447555.3464847.pdf", "url": "https://authors.library.caltech.edu/records/1fzny-bps82/files/3447555.3464847.pdf" }, "pub_year": "2021", "author_list": "Werner, Lucien; Wierman, Adam; et al." }, { "id": "https://authors.library.caltech.edu/records/k57m3-z0d57", "eprint_id": 112753, "eprint_status": "archive", "datestamp": "2023-08-20 03:07:41", "lastmod": "2026-03-30 13:51:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bao-Chengying", "name": { "family": "Bao", "given": "Chengying" }, "orcid": "0000-0003-0697-508X" }, { "id": "Yuan-Zhiquan", "name": { "family": "Yuan", "given": "Zhiquan" } }, { "id": "Wu-Lue", "name": { "family": "Wu", "given": "Lue" }, "orcid": "0000-0002-7503-7057" }, { "id": "Suh-Myoung-Gyun", "name": { "family": "Suh", "given": "Myoung-Gyun" }, "orcid": "0000-0002-9527-0585" }, { "id": "Lin-Qiang", "name": { "family": "Lin", "given": "Qiang" } }, { "id": "Vahala-K-J", "name": { "family": "Vahala", "given": "Kerry" }, "orcid": "0000-0003-1783-1380" } ] }, "title": "Mid-infrared dual-comb spectroscopy with GHz resolution using soliton microcombs", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2021 The Author(s). \n\nThis work was supported by the DTRA (HD-TRA11810047), the AFSOR (FA9550-18-1-0353), the Resnick Institute at Caltech, and the Kavli Nanoscience Institute.\n\nPublished - Mid-infrared_dual-comb_spectroscopy_with_GHz_resolution_using_soliton_microcombs.pdf
", "abstract": "Microcomb based dual-comb spectroscopy of methane in the mid-infrared is demonstrated with GHz resolution. This fine resolution is enabled by generating spectrally densified mid-infrared combs via interleaved difference-frequency-generation.", "date": "2021-05", "date_type": "published", "publisher": "Optical Society of America", "place_of_pub": "Washington, DC", "pagerange": "Art. No. SM3A.6", "id_number": "CaltechAUTHORS:20220106-132231400", "isbn": "978-1-943580-91-0", "book_title": "2021 Conference on Lasers and Electro-Optics (CLEO)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220106-132231400", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Defense Threat Reduction Agency (DTRA)", "grant_number": "HD-TRA11810047" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-18-1-0353" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Kavli Nanoscience Institute" } ] }, "local_group": { "items": [ { "id": "Kavli-Nanoscience-Institute" }, { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1364/cleo_si.2021.sm3a.6", "primary_object": { "basename": "Mid-infrared_dual-comb_spectroscopy_with_GHz_resolution_using_soliton_microcombs.pdf", "url": "https://authors.library.caltech.edu/records/k57m3-z0d57/files/Mid-infrared_dual-comb_spectroscopy_with_GHz_resolution_using_soliton_microcombs.pdf" }, "pub_year": "2021", "author_list": "Bao, Chengying; Yuan, Zhiquan; et al." }, { "id": "https://authors.library.caltech.edu/records/9waas-jh028", "eprint_id": 105499, "eprint_status": "archive", "datestamp": "2023-08-19 21:15:52", "lastmod": "2026-03-30 16:44:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bao-Chengying", "name": { "family": "Bao", "given": "Chengying" } }, { "id": "Yuan-Zhiquan", "name": { "family": "Yuan", "given": "Zhiquan" } }, { "id": "Wang-Heming", "name": { "family": "Wang", "given": "Heming" }, "orcid": "0000-0003-3861-0624" }, { "id": "Wu-Lue", "name": { "family": "Wu", "given": "Lue" }, "orcid": "0000-0002-7503-7057" }, { "id": "Shen-Boqiang", "name": { "family": "Shen", "given": "Boqiang" }, "orcid": "0000-0003-0697-508X" }, { "id": "Sung-Keeyoon", "name": { "family": "Sung", "given": "Keeyoon" } }, { "id": "Leifer-Stephanie-D", "name": { "family": "Leifer", "given": "Stephanie" }, "orcid": "0000-0002-8980-7825" }, { "id": "Lin-Qiang", "name": { "family": "Lin", "given": "Qiang" } }, { "id": "Vahala-K-J", "name": { "family": "Vahala", "given": "Kerry" }, "orcid": "0000-0003-1783-1380" } ] }, "title": "Interleaved difference-frequency-generation for mid-infrared microcomb spectral densification", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2020 The Author(s). \n\nWe acknowledge support from the DTRA (HD-TRA11810047); the AFSOR (FA9550-18-1-0353) and the Resnick Institute at Caltech.\n\nPublished - 09193811.pdf
", "abstract": "Generation of mid-infrared combs (3.3 micron band) with GigaHertz line spacing is demonstrated by interleaved difference-frequency-generation. The method, applied to a 22 GHz repetition-rate microcomb, is useful for spectral densification of sparse microcomb spectra.", "date": "2020-05", "date_type": "published", "publisher": "Optical Society of America", "place_of_pub": "Washington, DC", "pagerange": "Art. No. SW3J.1", "id_number": "CaltechAUTHORS:20200923-133250387", "isbn": "9781943580767", "book_title": "2020 Conference on Lasers and Electro-Optics (CLEO)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200923-133250387", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Defense Threat Reduction Agency (DTRA)", "grant_number": "HD-TRA11810047" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-18-1-0353" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1364/cleo_si.2020.sw3j.1", "primary_object": { "basename": "09193811.pdf", "url": "https://authors.library.caltech.edu/records/9waas-jh028/files/09193811.pdf" }, "pub_year": "2020", "author_list": "Bao, Chengying; Yuan, Zhiquan; et al." }, { "id": "https://authors.library.caltech.edu/records/pqhxh-6sk78", "eprint_id": 96748, "eprint_status": "archive", "datestamp": "2023-08-19 18:51:17", "lastmod": "2026-03-31 00:24:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Guo-Linqi", "name": { "family": "Guo", "given": "Linqi" } }, { "id": "Liang-Chen", "name": { "family": "Liang", "given": "Chen" } }, { "id": "Zocca-A", "name": { "family": "Zocca", "given": "Alessandro" }, "orcid": "0000-0001-6585-4785" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" } } ] }, "title": "Less is More: Real-time Failure Localization in Power Systems", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 IEEE.\n\nThis work has been supported by Resnick Fellowship, Linde Institute Research Award, NWO Rubicon grant 680.50.1529., NSF grants through PFI:AIR-TT award 1602119, EPCN 1619352, CNS 1545096, CCF 1637598, ECCS 1619352, CNS 1518941, CPS 154471, AitF 1637598, ARPA-E grant through award DE-AR0000699 (NODES) and GRID DATA, DTRA through grant HDTRA 1-15-1-0003 and Skoltech through collaboration agreement 1075-MRA.\n\nSubmitted - 1904.05461.pdf
", "abstract": "Cascading failures in power systems exhibit nonlocal propagation patterns, which make the analysis and mitigation of failures difficult. In this work, we propose a distributed control framework inspired by the recently proposed concepts of unified controller and network tree-partition that offers strong guarantees in both the mitigation and localization of cascading failures in power systems. In this framework, the transmission network is partitioned into several control areas which are connected in a tree structure, and the unified controller is adopted by generators or controllable loads for fast timescale disturbance response. After an initial failure, the proposed strategy always prevents successive failures from happening, and regulates the system to the desired steady state where the impact of initial failures are localized as much as possible. For extreme failures that cannot be localized, the proposed framework has a configurable design, that progressively involves and coordinates more control areas for failure mitigation and, as a last resort, imposes minimal load shedding. We compare the proposed control framework with Automatic Generation Control (AGC) on the IEEE 118-bus test system. Simulation results show that our novel framework greatly improves the system robustness in terms of the N - 1 security standard, and localizes the impact of initial failures in majority of the load profiles that are examined. Moreover, the proposed framework incurs significantly less load loss, if any, compared to AGC.", "date": "2019-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3871-3877", "id_number": "CaltechAUTHORS:20190626-143544929", "isbn": "978-1-7281-1398-2", "book_title": "2019 IEEE 58th Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190626-143544929", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Resnick Sustainability Institute" }, { "agency": "Linde Institute of Economic and Management Science" }, { "agency": "Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)", "grant_number": "680.50.1529" }, { "agency": "NSF", "grant_number": "IIP-1602119" }, { "agency": "NSF", "grant_number": "ECCS-1619352" }, { "agency": "NSF", "grant_number": "CNS-1545096" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "ECCS-1619352" }, { "agency": "NSF", "grant_number": "CNS-1518941" }, { "agency": "NSF", "grant_number": "CPS-154471" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "Advanced Research Projects Agency-Energy (ARPA-E)", "grant_number": "DE-AR0000699" }, { "agency": "Defense Threat Reduction Agency (DTRA)", "grant_number": "HDTRA 1-15-1-0003" }, { "agency": "Skoltech", "grant_number": "1075-MRA" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC40024.2019.9029393", "primary_object": { "basename": "1904.05461.pdf", "url": "https://authors.library.caltech.edu/records/pqhxh-6sk78/files/1904.05461.pdf" }, "pub_year": "2019", "author_list": "Guo, Linqi; Liang, Chen; et al." }, { "id": "https://authors.library.caltech.edu/records/p40d5-h5819", "eprint_id": 100181, "eprint_status": "archive", "datestamp": "2023-08-19 18:08:35", "lastmod": "2026-03-31 04:45:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lee-Zachary-J", "name": { "family": "Lee", "given": "Zachary J." } }, { "id": "Johansson-D", "name": { "family": "Johansson", "given": "Daniel" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "ACN-Sim: An Open-Source Simulator for Data-Driven Electric Vehicle Charging Research", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2019 IEEE. \n\nThis material is based upon work supported by NSF through grants CCF 1637598, ECCS 1619352, and CPS including grant 1739355, as well fellowship support through the NSF Graduate Research Fellowship Program 1745301 and Resnick Sustainability Institute. We would like to thank the team at PowerFlex, especially Cheng Jin, Ted Lee and George Lee, as well as Rand Lee, James Anderson, Umar Hashmi, and Jorn Reniers for providing data, expertise and ideas to this project.", "abstract": "Smart electric vehicle charging has recently garnered significant attention in the research community due to need to charge vast numbers of electric vehicles (EVs) economically, as well as the potential of providing grid services using EVs. However, research into practical online charging algorithms has been hampered by the lack of a widely available, realistic simulation environment in which to evaluate algorithms and test assumptions. To meet this need, we have developed ACN-Sim, a data-driven, open-source simulator based on our experience building and operating real-world charging systems. ACN-Sim provides a modular, extensible architecture which models the complexity of real charging systems, including battery charging behavior and unbalanced three-phase infrastructure. In addition, ACN-Sim integrates with a broader ecosystem of research tools for EV charging, including ACN-Data, an open dataset of EV charging sessions to provide realistic simulation scenarios, and ACN-Live, a framework for field-testing charging algorithms.", "date": "2019-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-6", "id_number": "CaltechAUTHORS:20191204-131602950", "isbn": "978-1-5386-8099-5", "book_title": "2019 IEEE International Conference on Communications, Control, and Computing Technologies for Smart Grids", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191204-131602950", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "ECCS-1619352" }, { "agency": "NSF", "grant_number": "ECCS-1739355" }, { "agency": "NSF Graduate Research Fellowship", "grant_number": "DGE-1745301" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/smartgridcomm.2019.8909765", "pub_year": "2019", "author_list": "Lee, Zachary J.; Johansson, Daniel; et al." }, { "id": "https://authors.library.caltech.edu/records/fzbcd-mxm43", "eprint_id": 97070, "eprint_status": "archive", "datestamp": "2023-08-19 15:40:57", "lastmod": "2026-03-31 15:34:25", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bao-Chengying", "name": { "family": "Bao", "given": "Chengying" } }, { "id": "Suh-Myoung-Gyun", "name": { "family": "Suh", "given": "Myoung-Gyun" }, "orcid": "0000-0002-9527-0585" }, { "id": "Vahala-K-J", "name": { "family": "Vahala", "given": "Kerry" }, "orcid": "0000-0003-1783-1380" } ] }, "title": "Dual-comb imaging using soliton microcombs", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2019 The Author(s). \n\nWe acknowledge support from the Air Force Office of Scientific Research (FA9550-18-1-0353), the Kavli Nanoscience Institute and the Resnick Institute at Caltech.\n\nPublished - 08749254.pdf
", "abstract": "We demonstrate rapid imaging using dual-microcomb interferometry. One of the soliton microcombs is spatially dispersed into two dimensions to record spatial information and the image is read out by multi-heterodyne with the second microcomb.", "date": "2019-05", "date_type": "published", "publisher": "Optical Society of America", "place_of_pub": "Washington, DC", "pagerange": "Art. No. STh4J.3", "id_number": "CaltechAUTHORS:20190711-150915486", "isbn": "978-1-943580-57-6", "book_title": "CLEO: Science and Innovations 2019", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190711-150915486", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-18-1-0353" }, { "agency": "Kavli Nanoscience Institute" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" }, { "id": "Kavli-Nanoscience-Institute" } ] }, "doi": "10.1364/CLEO_SI.2019.STh4J.3", "primary_object": { "basename": "08749254.pdf", "url": "https://authors.library.caltech.edu/records/fzbcd-mxm43/files/08749254.pdf" }, "pub_year": "2019", "author_list": "Bao, Chengying; Suh, Myoung-Gyun; et al." }, { "id": "https://authors.library.caltech.edu/records/5hxj8-1q081", "eprint_id": 95494, "eprint_status": "archive", "datestamp": "2023-08-19 14:44:35", "lastmod": "2026-03-31 13:18:32", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vyatskikh-A", "name": { "family": "Vyatskikh", "given": "Andrey" }, "orcid": "0000-0002-6917-6931" }, { "id": "Ng-Ryan-C", "name": { "family": "Ng", "given": "Ryan C." }, "orcid": "0000-0002-0527-9130" }, { "id": "Edwards-Bryce", "name": { "family": "Edwards", "given": "Bryce" } }, { "id": "Greer-J-R", "name": { "family": "Greer", "given": "Julia R." }, "orcid": "0000-0002-9675-1508" } ] }, "title": "Additive manufacturing of titanium dioxide for dielectric photonic crystals", "ispublished": "unpub", "full_text_status": "public", "keywords": "additive manufacturing, pre-ceramic polymer, titanium dioxide, titania, photonic crystal", "note": "\u00a9 2019 Society of Photo-Optical Instrumentation Engineers (SPIE).\n\nThe authors are grateful for the support of JRG's Vannevar Bush Faculty Fellowship and AV's Resnick Sustainability Institute at Caltech Fellowship and NIH Biotechnology Leadership Pre-Doctoral Training Program support. The authors thank Professor George R. Rossman (Caltech) for his assistance with Raman spectroscopy and FTIR.\n\nPublished - 109300H.pdf
", "abstract": "Fabrication of 3D dielectric photonic crystals in the visible and in the infrared range typically requires sub-micron structural features and high-refractive index materials. We developed a template-free additive manufacturing (AM) process based on direct laser writing (DLW) that can create complex 3D architectures out of titania (TiO_2) with ~100 nm resolution. In this process, we synthesize hybrid organic-inorganic materials that contain titanium clusters coordinated with acrylic ligands to prepare a photoresist that is amenable to two-photon lithography (TPL). We sculpt a pre-ceramic architecture using TPL and then pyrolyze in air at 900\u00b0C to remove the organic constituents to produce a replica of the original structure with ~70% reduced linear dimensions. Energy-Dispersive Spectroscopy (EDS) and Raman spectroscopy confirm the constituent solid to consist predominantly out of rutile titania.\nWe demonstrate this process by fabricating titania woodpile structures with lateral dimensions of 70 \u00d7 70 \u03bcm and lateral periodicities between 1.0 and 1.3 \u03bcm. Fourier Transform Infrared (FTIR) spectroscopy reveals passive tuning of the reflectance peak between 1.7 and 2.3 \u03bcm, which agrees with Plane Wave Expansion simulations. This titania AM process offers a promising pathway to efficiently fabricate complex 3D nano-architectures out of a high-index material for 3D dielectric photonic crystals in the visible and the infrared.", "date": "2019-03-04", "date_type": "published", "publisher": "Society of Photo-optical Instrumentation Engineers (SPIE)", "id_number": "CaltechAUTHORS:20190514-124438045", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190514-124438045", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Vannevar Bush Faculty Fellowship" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "NIH Biotechnology Leadership Pre-Doctoral Training Program" } ] }, "local_group": { "items": [ { "id": "Rosen-Bioengineering-Center" }, { "id": "Resnick-Sustainability-Institute" } ] }, "contributors": { "items": [ { "id": "von-Freymann-G", "name": { "family": "von Freymann", "given": "Georg" } }, { "id": "Shoenfeld-W-V", "name": { "family": "Schoenfeld", "given": "Winston V." } }, { "id": "Rumpf-R-C", "name": { "family": "Rumpf", "given": "Raymond C." } } ] }, "doi": "10.1117/12.2507076", "primary_object": { "basename": "109300H.pdf", "url": "https://authors.library.caltech.edu/records/5hxj8-1q081/files/109300H.pdf" }, "pub_year": "2019", "author_list": "Vyatskikh, Andrey; Ng, Ryan C.; et al." }, { "id": "https://authors.library.caltech.edu/records/76deq-fe812", "eprint_id": 92578, "eprint_status": "archive", "datestamp": "2023-08-19 13:04:15", "lastmod": "2026-04-01 02:40:55", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Guo-Linqi", "name": { "family": "Guo", "given": "Linqi" } }, { "id": "Liang-Chen", "name": { "family": "Liang", "given": "Chen" } }, { "id": "Zocca-A", "name": { "family": "Zocca", "given": "Alessandro" }, "orcid": "0000-0001-6585-4785" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" } } ] }, "title": "Failure Localization in Power Systems via Tree Partitions", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 IEEE. \n\nThis work has been supported by Resnick Fellowship, Linde Institute Research Award, NWO Rubicon grant 680.50.1529., NSF grants through PFI:AIR-TT award 1602119, EPCN 1619352, CNS 1545096, CCF 1637598, ECCS 1619352, CNS 1518941, CPS 154471, AitF 1637598, ARPA-E grant through award DE-AR0000699 (NODES) and GRID DATA, DTRA through grant HDTRA 1-15-1-0003 and Skoltech through collaboration agreement 1075-MRA.\n\nSubmitted - 1803.08551.pdf
", "abstract": "Cascading failures in power systems propagate non-locally, making the control and mitigation of outages extremely hard. In this work, we use the emerging concept of the tree partition of transmission networks to provide an analytical characterization of line failure localizability in transmission systems. Our results rigorously establish the well perceived intuition in power community that failures cannot cross bridges, and reveal a finer-grained concept that encodes more precise information on failure propagations within tree-partition regions. Specifically, when a non-bridge line is tripped, the impact of this failure only propagates within well-defined components, which we refer to as cells, of the tree partition defined by the bridges. In contrast, when a bridge line is tripped, the impact of this failure propagates globally across the network, affecting the power flow on all remaining transmission lines. This characterization suggests that it is possible to improve the system robustness by temporarily switching off certain transmission lines, so as to create more, smaller components in the tree partition; thus spatially localizing line failures and making the grid less vulnerable to large-scale outages. We illustrate this approach using the IEEE 118-bus test system and demonstrate that switching off a negligible portion of transmission lines allows the impact of line failures to be significantly more localized without substantial changes in line congestion.", "date": "2018-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "6832-6839", "id_number": "CaltechAUTHORS:20190201-135634765", "isbn": "9781538613955", "book_title": "2018 IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190201-135634765", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Resnick Sustainability Institute" }, { "agency": "Linde Institute of Economic and Management Science" }, { "agency": "Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)", "grant_number": "680.50.1529" }, { "agency": "NSF", "grant_number": "IIP-1602119" }, { "agency": "NSF", "grant_number": "ECCS-1619352" }, { "agency": "NSF", "grant_number": "CNS-1545096" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "ECCS-1619352" }, { "agency": "NSF", "grant_number": "CNS-1518941" }, { "agency": "NSF", "grant_number": "CPS-154471" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "Advanced Research Projects Agency-Energy (ARPA-E)", "grant_number": "DE-AR0000699" }, { "agency": "Defense Threat Reduction Agency (DTRA)", "grant_number": "HDTRA 1-15-1-0003" }, { "agency": "Skoltech", "grant_number": "1075-MRA" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/cdc.2018.8619562", "primary_object": { "basename": "1803.08551.pdf", "url": "https://authors.library.caltech.edu/records/76deq-fe812/files/1803.08551.pdf" }, "pub_year": "2018", "author_list": "Guo, Linqi; Liang, Chen; et al." }, { "id": "https://authors.library.caltech.edu/records/ezh7h-8fd72", "eprint_id": 92626, "eprint_status": "archive", "datestamp": "2023-08-19 13:04:55", "lastmod": "2026-03-31 23:01:27", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Guo-Linqi", "name": { "family": "Guo", "given": "Linqi" } }, { "id": "Zhao-Changhong", "name": { "family": "Zhao", "given": "Changhong" }, "orcid": "0000-0003-0539-8591" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Graph Laplacian Spectrum and Primary Frequency Regulation", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2018 IEEE. \n\nThe authors thank Janusz Bialek and Oleg Khamisov from Skoltech for helpful discussions. This work has been supported by Resnick Research Fellowship, Linde Institute Research Award, DOE through the ENERGISE program (Award #DE-EE-0007998), NSF grants through CCF 1637598, ECCS 1619352, CNS 1545096, ARPA-E grant through award DE-AR0000699 (NODES) and GRID DATA, DTRA through grant HDTRA 1-15-1-0003 and Skoltech through collaboration agreement 1075-MRA.\n\nSubmitted - 1803.03905.pdf
", "abstract": "We present a framework based on spectral graph theory that captures the interplay among network topology, system inertia, and generator and load damping in determining the overall grid behavior and performance. Specifically, we show that the impact of network topology on a power system can be quantified through the network Laplacian eigenvalues, and such eigenvalues determine the grid robustness against low frequency disturbances. Moreover, we can explicitly decompose the frequency signal along scaled Laplacian eigenvectors when damping-inertia ratios are uniform across buses. The insight revealed by this framework partially explains why load-side participation in frequency regulation not only makes the system respond faster, but also helps lower the system nadir after a disturbance. Finally, by presenting a new controller specifically tailored to suppress high frequency disturbances, we demonstrate that our results can provide useful guidelines in the controller design for load-side primary frequency regulation. This improved controller is simulated on the IEEE 39-bus New England interconnection system to illustrate its robustness against high frequency oscillations compared to both the conventional droop control and a recent controller design.", "date": "2018-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "158-165", "id_number": "CaltechAUTHORS:20190204-110323666", "isbn": "978-1-5386-1395-5", "book_title": "2018 IEEE Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190204-110323666", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Resnick Sustainability Institute" }, { "agency": "Linde Institute of Economic and Management Science" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-EE-0007998" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "ECCS-1619352" }, { "agency": "NSF", "grant_number": "CNS-1545096" }, { "agency": "Advanced Research Projects Agency-Energy (ARPA-E)", "grant_number": "DE-AR0000699" }, { "agency": "Defense Threat Reduction Agency (DTRA)", "grant_number": "HDTRA 1-15-1-0003" }, { "agency": "Skoltech", "grant_number": "1075-MRA" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2018.8619252", "primary_object": { "basename": "1803.03905.pdf", "url": "https://authors.library.caltech.edu/records/ezh7h-8fd72/files/1803.03905.pdf" }, "pub_year": "2018", "author_list": "Guo, Linqi; Zhao, Changhong; et al." }, { "id": "https://authors.library.caltech.edu/records/7cwt2-6p715", "eprint_id": 89428, "eprint_status": "archive", "datestamp": "2023-08-19 09:33:49", "lastmod": "2026-03-31 22:02:51", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Guo-Linqi", "name": { "family": "Guo", "given": "Linqi" } }, { "id": "Zhao-Changhong", "name": { "family": "Zhao", "given": "Changhong" }, "orcid": "0000-0003-0539-8591" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Cyber Network Design for Secondary Frequency Regulation: A Spectral Approach", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2018 IEEE.\n\nThe authors thank Professor Janusz Bialek from Skoltech for helpful discussions. This work has been supported by Resnick Fellowship, Linde Institute Research Award, DOE through the ENERGISE program (Award #DE-EE-0007998), NSF grants through CCF 1637598, ECCS 1619352, CNS 1545096, ARPA-E grant through award DE-AR0000699 (NODES) and GRID DATA, DTRA through grant HDTRA 1-15-1-0003 and Skoltech through collaboration agreement 1075-MRA.", "abstract": "We present a preliminary theoretical framework based on spectral graph theory that captures how the cyber topology of a distributed secondary frequency control scheme impacts the stability, optimality, and transient performance of our power system as a cyber-physical network. We show that a collection of polynomials defined in terms of the cyber and physical Laplacian eigenvalues encode information on the interplay between cyber and physical networks. It is demonstrated that to understand the impact of adding cyber connectivity, one should separate the low-damping and high-damping regimes. Although adding cyber connectivity always improves the performance for high-damping systems, it is not the case for low-damping scenarios. Based on the theoretical study, we discuss how a good cyber network should be designed. Our empirical study shows that for practical systems, the number of communication channels that is needed to achieve near-optimal performance is usually less than twice the number of buses.", "date": "2018-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-7", "id_number": "CaltechAUTHORS:20180906-143422101", "isbn": "978-1-910963-10-4", "book_title": "2018 Power Systems Computation Conference (PSCC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180906-143422101", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Resnick Sustainability Institute" }, { "agency": "Ronald And Maxine Linde Center for Global Environmental Science" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-EE-0007998" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "ECCS-1619352" }, { "agency": "NSF", "grant_number": "CNS-1545096" }, { "agency": "Advanced Research Projects Agency-Energy (ARPA-E)", "grant_number": "DE-AR0000699" }, { "agency": "Defense Threat Reduction Agency (DTRA)", "grant_number": "HDTRA 1-15-1-0003" }, { "agency": "Skoltech", "grant_number": "1075-MRA" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.23919/PSCC.2018.8442814", "pub_year": "2018", "author_list": "Guo, Linqi; Zhao, Changhong; et al." }, { "id": "https://authors.library.caltech.edu/records/hd7br-x6z92", "eprint_id": 90772, "eprint_status": "archive", "datestamp": "2023-08-19 03:30:33", "lastmod": "2026-04-01 20:11:19", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kelzenberg-M-D", "name": { "family": "Kelzenberg", "given": "Michael D." }, "orcid": "0000-0002-6249-2827" }, { "id": "Espinet-Gonz\u00e1lez-P", "name": { "family": "Espinet-Gonz\u00e1lez", "given": "Pilar" }, "orcid": "0000-0002-7656-0077" }, { "id": "Vaidya-N", "name": { "family": "Vaidya", "given": "Nina" } }, { "id": "Roy-T-A", "name": { "family": "Roy", "given": "Tatiana A." } }, { "id": "Warmann-E-C", "name": { "family": "Warmann", "given": "Emily C." }, "orcid": "0000-0002-2810-4608" }, { "id": "Naqavi-A", "name": { "family": "Naqavi", "given": "Ali" } }, { "id": "Loke-S-P", "name": { "family": "Loke", "given": "Samuel P." } }, { "id": "Huang-Jing-Shun", "name": { "family": "Huang", "given": "Jing-Shun" }, "orcid": "0000-0002-7531-4691" }, { "id": "Vinogradova-T-G", "name": { "family": "Vinogradova", "given": "Tatiana G." } }, { "id": "Messer-A-J", "name": { "family": "Messer", "given": "Alexander J." } }, { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Gdoutos-E-E", "name": { "family": "Gdoutos", "given": "Eleftherios E." } }, { "id": "Royer-F", "name": { "family": "Royer", "given": "Fabien" } }, { "id": "Hajimiri-A", "name": { "family": "Hajimiri", "given": "Ali" }, "orcid": "0000-0001-6736-8019" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Atwater-H-A", "name": { "family": "Atwater", "given": "Harry A." }, "orcid": "0000-0001-9435-0201" } ] }, "title": "Design and Prototyping Efforts for the Space Solar Power Initiative", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "space solar power, concentrator photovoltaics, thermal management", "note": "\u00a9 2017 IEEE. \n\nWe acknowledge financial support from Northrop Grumman. This effort made use of facilities provided by the Kavli Nanoscience Institute, the Molecular Materials Research Center, the Resnick Institute, and the Joint Center for Artificial Photosynthesis at Caltech. We acknowledge the helpful contributions of Mark Kruer, Mike Levesque, and Erik Kurman at Northrop Grumman; Lynn Rodman at Nexolve; and Allen Smith at ABET.", "abstract": "The Space Solar Power Initiative (SSPI) seeks to enable reliable, cost-effective baseload power generation from large-scale solar power stations in space. We propose an ultralight, modular power station, having specific power in the range of 1\u201310 kW/kg for the photovoltaic (PV) collection subsystem. The building block of the power station is the 'tile,' a self-contained element that performs PV energy collection, conversion to radio frequency (RF), and transmission to earth. To minimize PV mass, we select a 1D, 10\u201320X parabolic trough concentrator geometry, which provides cooling and radiation shielding for the cells, and which folds flat for deployment. Here, we discuss the design, fabrication, and testing of the initial PV tile prototypes.", "date": "2017-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "558-561", "id_number": "CaltechAUTHORS:20181108-154443049", "isbn": "978-1-5090-5605-7", "book_title": "2017 IEEE 44th Photovoltaic Specialist Conference (PVSC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181108-154443049", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "local_group": { "items": [ { "id": "Kavli-Nanoscience-Institute" }, { "id": "Resnick-Sustainability-Institute" }, { "id": "JCAP" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.1109/PVSC.2017.8366621", "pub_year": "2017", "author_list": "Kelzenberg, Michael D.; Espinet-Gonz\u00e1lez, Pilar; et al." }, { "id": "https://authors.library.caltech.edu/records/bvyep-y7s87", "eprint_id": 78219, "eprint_status": "archive", "datestamp": "2023-08-19 03:20:59", "lastmod": "2026-04-01 17:57:12", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Islam-M-A", "name": { "family": "Islam", "given": "Mohammad A." } }, { "id": "Ren-Xiaoqi", "name": { "family": "Ren", "given": "Xiaoqi" }, "orcid": "0000-0002-1121-9046" }, { "id": "Ren-Shaolei", "name": { "family": "Ren", "given": "Shaolei" } }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" } } ] }, "title": "A Spot Capacity Market to Increase Power Infrastructure Utilization in Multi-Tenant Data Centers", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2017 Copyright held by the owner/author(s). \n\nThis work was supported in part by the U.S. NSF under grants\nCNS-1551661, CNS-1565474, ECCS-1610471, AitF-1637598 and CNS-1518941, and the Resnick Sustainability Institute at Caltech.", "abstract": "Despite the common practice of oversubscription, power capacity is largely under-utilized in data centers. A significant factor driving this under-utilization is fluctuation of the aggregate power demand, resulting in unused \"spot (power) capacity\". In this paper, we tap into spot capacity for improving power infrastructure utilization in multi-tenant data centers, an important but under-explored type of data center where multiple tenants house their own physical servers. We propose a novel spot capacity market, called SpotDC, to allocate spot capacity to tenants on demand. Specifically, SpotDC extracts tenants' rack-level spot capacity demand through an elastic demand function, based on which the operator sets the market price for spot capacity allocation. We evaluate SpotDC using both testbed experiments and simulations, demonstrating that SpotDC improves power infrastructure utilization and creates a \"win-win\" situation: the data center operator increases its profit (by nearly 10%), while tenants improve their performance (by 1.2{1.8x on average, yet at a marginal cost).", "date": "2017-06", "date_type": "published", "publisher": "ACM", "place_of_pub": "New York, NY", "pagerange": "19-20", "id_number": "CaltechAUTHORS:20170614-154927009", "isbn": "978-1-4503-5032-7", "book_title": "Proceedings of the 2017 ACM SIGMETRICS / International Conference on Measurement and Modeling of Computer Systems - SIGMETRICS '17 Abstracts", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170614-154927009", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-1551661" }, { "agency": "NSF", "grant_number": "CNS-1565474" }, { "agency": "NSF", "grant_number": "ECCS-1610471" }, { "agency": "NSF", "grant_number": "CCF-1637598" }, { "agency": "NSF", "grant_number": "CNS-1518941" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1145/3078505.3078542", "pub_year": "2017", "author_list": "Islam, Mohammad A.; Ren, Xiaoqi; et al." }, { "id": "https://authors.library.caltech.edu/records/g3erz-2jk31", "eprint_id": 90779, "eprint_status": "archive", "datestamp": "2023-08-19 03:30:41", "lastmod": "2026-04-01 07:02:06", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Espinet-Gonz\u00e1lez-P", "name": { "family": "Espinet-Gonz\u00e1lez", "given": "Pilar" }, "orcid": "0000-0002-7656-0077" }, { "id": "Vinogradova-T-G", "name": { "family": "Vinogradova", "given": "Tatiana" } }, { "id": "Kelzenberg-M-D", "name": { "family": "Kelzenberg", "given": "Michael D." }, "orcid": "0000-0002-6249-2827" }, { "id": "Messer-A-J", "name": { "family": "Messer", "given": "Alexander" } }, { "id": "Warmann-E-C", "name": { "family": "Warmann", "given": "Emily C." }, "orcid": "0000-0002-2810-4608" }, { "id": "Peterson-C", "name": { "family": "Peterson", "given": "Chris" } }, { "id": "Vaidya-N", "name": { "family": "Vaidya", "given": "Nina" } }, { "id": "Naqavi-A", "name": { "family": "Naqavi", "given": "Ali" } }, { "id": "Huang-Jing-Shun", "name": { "family": "Huang", "given": "Jing-Shun" }, "orcid": "0000-0002-7531-4691" }, { "id": "Loke-S-P", "name": { "family": "Loke", "given": "Samuel P." } }, { "id": "Walker-D", "name": { "family": "Walker", "given": "Don" } }, { "id": "Mann-C-J", "name": { "family": "Mann", "given": "Colin J." } }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Atwater-H-A", "name": { "family": "Atwater", "given": "Harry A." }, "orcid": "0000-0001-9435-0201" } ] }, "title": "Impact of Space Radiation Environment on Concentrator Photovoltaic Systems", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Concentrator photovoltaic systems, concentrator solar cells, space radiation modeling, radiation tests, space solar power, shielding", "note": "\u00a9 2017 IEEE. \n\nWe acknowledge financial support from Northrop Grumman. This effort made use of facilities provided by the Kavli Nanoscience Institute, the Material Molecular Research Center (MMRC), the Resnick Institute, and the Joint Center for Artificial Photosynthesis, at Caltech.", "abstract": "Concentrator photovoltaic systems can provide supplementary shielding against high energy particles. In this paper we compare the radiation environment that the same solar cell would experience in a flat-plate module versus in a parabolic mirror concentrator system. We have observed that the shielding provided by the concentrator system is remarkable. In order to obtain an accurate prediction of the overall shield needed in our concentrator system triple-junction space solar cells have been irradiated on the edge with 350-keV protons at a fluence of 10^(12) p^+cm^(-2). A mild degradation of the open circuit voltage was measured (~70 mV).", "date": "2017-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "512-516", "id_number": "CaltechAUTHORS:20181109-074226646", "isbn": "978-1-5090-5605-7", "book_title": "2017 IEEE 44th Photovoltaic Specialist Conference (PVSC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181109-074226646", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "local_group": { "items": [ { "id": "Kavli-Nanoscience-Institute" }, { "id": "Resnick-Sustainability-Institute" }, { "id": "JCAP" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.1109/PVSC.2017.8366020", "pub_year": "2017", "author_list": "Espinet-Gonz\u00e1lez, Pilar; Vinogradova, Tatiana; et al." }, { "id": "https://authors.library.caltech.edu/records/0xnyf-zv194", "eprint_id": 90780, "eprint_status": "archive", "datestamp": "2023-08-19 03:30:51", "lastmod": "2026-04-01 16:37:49", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Vaidya-N", "name": { "family": "Vaidya", "given": "Nina" } }, { "id": "Kelzenberg-M-D", "name": { "family": "Kelzenberg", "given": "Michael D." }, "orcid": "0000-0002-6249-2827" }, { "id": "Espinet-Gonz\u00e1lez-P", "name": { "family": "Espinet-Gonz\u00e1lez", "given": "Pilar" }, "orcid": "0000-0002-7656-0077" }, { "id": "Vinogradova-T-G", "name": { "family": "Vinogradova", "given": "Tatiana G." } }, { "id": "Huang-Jing-Shun", "name": { "family": "Huang", "given": "Jing-Shun" }, "orcid": "0000-0002-7531-4691" }, { "id": "Leclerc-C", "name": { "family": "Leclerc", "given": "Christophe" } }, { "id": "Naqavi-A", "name": { "family": "Naqavi", "given": "Ali" } }, { "id": "Warmann-E-C", "name": { "family": "Warmann", "given": "Emily C." }, "orcid": "0000-0002-2810-4608" }, { "id": "Pellegrino-S", "name": { "family": "Pellegrino", "given": "Sergio" }, "orcid": "0000-0001-9373-3278" }, { "id": "Atwater-H-A", "name": { "family": "Atwater", "given": "Harry A." }, "orcid": "0000-0001-9435-0201" } ] }, "title": "Lightweight Carbon Fiber Mirrors for Solar Concentrator Applications", "ispublished": "unpub", "full_text_status": "public", "keywords": "mirrors, solar energy, optical device fabrication, polymers, ray tracing, space solar, optical design", "note": "\u00a9 2017 IEEE. \n\nWe acknowledge funding from Northrop Grumman Corporation. This effort made use of facilities provided by the Kavli Nanoscience Institute, the Molecular Materials Research Center, the Resnick Institute, and the Joint Center for Artificial Photosynthesis at Caltech. We acknowledge the helpful contributions of Mark Kruer, Mike Levesque, and Erik Kurman at Northrop Grumman.\n\nSubmitted - 1810.09529.pdf
", "abstract": "Lightweight parabolic mirrors for solar concentrators have been fabricated using carbon fiber reinforced polymer (CFRP) and a nanometer scale optical surface smoothing technique. The smoothing technique improved the surface roughness of the CFRP surface from ~3 \u03bcm root mean square (RMS) for as-cast to ~5 nm RMS after smoothing. The surfaces were then coated with metal, which retained the sub-wavelength surface roughness, to produce a high-quality specular reflector. The mirrors were tested in an 11x geometrical concentrator configuration and achieved an optical efficiency of 78% under an AM0 solar simulator. With further development, lightweight CFRP mirrors will enable dramatic improvements in the specific power, power per unit mass, achievable for concentrated photovoltaics in space.", "date": "2017-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "572-577", "id_number": "CaltechAUTHORS:20181109-075349019", "isbn": "978-1-5090-5605-7", "book_title": "2017 IEEE 44th Photovoltaic Specialist Conference (PVSC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181109-075349019", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Northrop Grumman Corporation" } ] }, "local_group": { "items": [ { "id": "Kavli-Nanoscience-Institute" }, { "id": "Resnick-Sustainability-Institute" }, { "id": "JCAP" }, { "id": "Space-Solar-Power-Project" } ] }, "doi": "10.48550/arXiv.1810.09529", "primary_object": { "basename": "1810.09529.pdf", "url": "https://authors.library.caltech.edu/records/0xnyf-zv194/files/1810.09529.pdf" }, "pub_year": "2017", "author_list": "Vaidya, Nina; Kelzenberg, Michael D.; et al." }, { "id": "https://authors.library.caltech.edu/records/6qqbz-5vk54", "eprint_id": 80290, "eprint_status": "archive", "datestamp": "2023-08-19 00:21:23", "lastmod": "2026-04-02 15:49:02", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lee-George", "name": { "family": "Lee", "given": "George" } }, { "id": "Lee-Ted", "name": { "family": "Lee", "given": "Ted" } }, { "id": "Low-Zhi-H", "name": { "family": "Low", "given": "Zhi" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" }, { "id": "Ortega-C", "name": { "family": "Ortega", "given": "Christine" } } ] }, "title": "Adaptive charging network for electric vehicles", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Electric vehicles, adaptive charger, ACN deployment,\nadaptive algorithms", "note": "\u00a9 2016 IEEE. \n\nDate Added to IEEE Xplore: 24 April 2017. \n\nWe thank Caltech's CI2 Grant, Resnick Institute, the Emerging Technologies Coordinating Council of Utilities, the Moxie Foundation's FLoW Rocket Fund, and the NSF AIR award 1602119 for financial support and Karl Fredrik Erliksson for discussions. This work was done when George Lee, Ted Lee and Zhi Low were visitors at Caltech. Steven H. Low is a co-founder of PowerFlex.", "abstract": "We describe a snapshot of an adaptive charging network (ACN) for electric vehicles at Caltech. We overview the system design, from the power distribution system to advanced charger design to control and communication system and the software system that integrates the overall network. We present a simple mathematical formulation of the charging problem. We have collected three months' of baseline charging data from the Caltech ACN. We demonstrate, by simulating a charging algorithm on the baseline data, the large potential benefit of ACN in saving infrastructure costs.", "date": "2016-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Washington, DC", "pagerange": "891-895", "id_number": "CaltechAUTHORS:20170811-093351619", "isbn": "978-1-5090-4545-7", "book_title": "2016 IEEE Global Conference on Signal and Information Processing (GlobalSIP)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170811-093351619", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Innovation Initiative (CI2)" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Emerging Technologies Coordinating Council of Utilities" }, { "agency": "Moxie Foundation" }, { "agency": "NSF", "grant_number": "IIP-1602119" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/GlobalSIP.2016.7905971", "pub_year": "2016", "author_list": "Lee, George; Lee, Ted; et al." }, { "id": "https://authors.library.caltech.edu/records/5szw4-8t878", "eprint_id": 73641, "eprint_status": "archive", "datestamp": "2023-08-20 03:52:44", "lastmod": "2026-04-05 16:43:48", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhao-Changhong", "name": { "family": "Zhao", "given": "Changhong" }, "orcid": "0000-0003-0539-8591" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven" }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Optimal decentralized primary frequency control in power networks", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 IEEE. \n\nThis work was supported by NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California Edison, National Science Council of Taiwan R.O.C. grant NSC 103-3113-P-008-001, Caltech Resnick Institute, and California Energy Commission's Small Grant Program through Grant 57360A/11-16.", "abstract": "We augment existing generator-side primary frequency control with load-side control that are local, ubiquitous, and continuous. The mechanisms on both the generator and the load sides are decentralized in that their control decisions are functions of locally measurable frequency deviations. These local algorithms interact over the network through nonlinear power flows. We design the local frequency feedback control so that any equilibrium point of the closed-loop system is the solution to an optimization problem that minimizes the total generation cost and user disutility subject to power balance across entire network. With Lyapunov method we derive a sufficient condition for any equilibrium point of the closed-loop system to be asymptotically stable. A simulation demonstrates improvement in both the transient and steady-state performance over the traditional control only on generators, even when the total control capacity remains the same.", "date": "2014-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2467-2473", "id_number": "CaltechAUTHORS:20170123-165356940", "isbn": "978-1-4673-6090-6", "book_title": "53rd IEEE Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170123-165356940", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 103-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "California Energy Commission Small Grant Program", "grant_number": "57360A/11-16" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2014.7039765", "pub_year": "2014", "author_list": "Zhao, Changhong and Low, Steven" }, { "id": "https://authors.library.caltech.edu/records/7ak7c-qp636", "eprint_id": 80072, "eprint_status": "archive", "datestamp": "2023-08-20 03:54:10", "lastmod": "2026-04-06 01:18:58", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Bose-Subhonmesh", "name": { "family": "Bose", "given": "Subhonmesh" }, "orcid": "0000-0002-3445-4479" }, { "id": "Cai-Desmond-W-H", "name": { "family": "Cai", "given": "Desmond W. H." }, "orcid": "0000-0001-9207-1890" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" } } ] }, "title": "The role of a market maker in networked Cournot competition", "ispublished": "unpub", "full_text_status": "public", "keywords": "Generators, Electricity supply industry, Vectors, Games, Mathematical model, Nash equilibrium, Pricing", "note": "\u00a9 2014 IEEE. \n\nSupported by: NSF through NetSE CNS 0911041, ARPA-E through\nGENI DE-AR0000226, EPAS-1307794, Southern California Edison, the National Science Council of Taiwan through NSC 103-3113-P-008-001, the Los Alamos National Lab (DoE), and Caltech's Resnick Institute.\n\nSubmitted - 1403.7286.pdf
Submitted - 1701.08896.pdf
", "abstract": "We study the role of a market maker (or market operator) in a transmission constrained electricity market. We model the market as a one-shot networked Cournot competition where generators supply quantity bids and load serving entities provide downward sloping inverse demand functions. This mimics the operation of a spot market in a deregulated market structure. In this paper, we focus on possible mechanisms employed by the market maker to balance demand and supply. In particular, we consider three candidate objective functions that the market maker optimizes - social welfare, residual social welfare, and consumer surplus. We characterize the existence of Generalized Nash Equilibrium (GNE) in this setting and demonstrate that market outcomes at equilibrium can be very different under the candidate objective functions.", "date": "2014-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "4479-4484", "id_number": "CaltechAUTHORS:20170810-101313051", "isbn": "978-1-4799-7746-8", "book_title": "53rd IEEE Annual Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170810-101313051", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "NSF", "grant_number": "EPAS-1307794" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 103-3113-P-008-001" }, { "agency": "Los Alamos National Laboratory" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2014.7040088", "primary_object": { "basename": "1403.7286.pdf", "url": "https://authors.library.caltech.edu/records/7ak7c-qp636/files/1403.7286.pdf" }, "related_objects": [ { "basename": "1701.08896.pdf", "url": "https://authors.library.caltech.edu/records/7ak7c-qp636/files/1701.08896.pdf" } ], "pub_year": "2014", "author_list": "Bose, Subhonmesh; Cai, Desmond W. H.; et al." }, { "id": "https://authors.library.caltech.edu/records/k2vxs-4nb81", "eprint_id": 54317, "eprint_status": "archive", "datestamp": "2023-08-20 03:10:21", "lastmod": "2026-04-05 16:47:42", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Mallada-E", "name": { "family": "Mallada", "given": "Enrique" }, "orcid": "0000-0003-1568-1833" }, { "id": "Zhao-Changhong", "name": { "family": "Zhao", "given": "Changhong" }, "orcid": "0000-0003-0539-8591" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven" }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Optimal load-side control for frequency regulation in smart grids", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2014 IEEE. \n\nThis work was supported by NSF NetSE grant CNS 0911041, ARPAE\ngrant DE-AR0000226, Southern California Edison, National Science\nCouncil of Taiwan R.O.C. grant NSC 103-3113-P-008-001, and Caltech\nResnick Institute.\n\nSubmitted - 1410.2931.pdf
", "abstract": "Frequency control rebalances supply and demand while maintaining the network state within operational margins. It is implemented using fast ramping reserves that are expensive and wasteful, and which are expected to grow with the increasing penetration of renewables. The most promising solution to this problem is the use of demand response, i.e. load participation in frequency control. Yet it is still unclear how to efficiently integrate load participation without introducing instabilities and violating operational constraints. In this paper we present a comprehensive load-side frequency control mechanism that can maintain the grid within operational constraints. Our controllers can rebalance supply and demand after disturbances, restore the frequency to its nominal value and preserve inter-area power flows. Furthermore, our controllers are distributed (unlike generation-side), can allocate load updates optimally, and can maintain line flows within thermal limits. We prove that such a distributed load-side control is globally asymptotically stable and illustrate its convergence with simulation.", "date": "2014-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "731-738", "id_number": "CaltechAUTHORS:20150203-091127023", "isbn": "978-1-4799-8009-3", "book_title": "52nd Annual Allerton Conference on Communication, Control, and Computing", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150203-091127023", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 103-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/ALLERTON.2014.7028527", "primary_object": { "basename": "1410.2931.pdf", "url": "https://authors.library.caltech.edu/records/k2vxs-4nb81/files/1410.2931.pdf" }, "pub_year": "2014", "author_list": "Mallada, Enrique; Zhao, Changhong; et al." }, { "id": "https://authors.library.caltech.edu/records/qy345-88r41", "eprint_id": 73649, "eprint_status": "archive", "datestamp": "2023-08-20 02:21:29", "lastmod": "2026-04-05 15:20:57", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gan-Lingwen", "name": { "family": "Gan", "given": "Lingwen" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Convexification of AC optimal power flow", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 by The Power Systems Computation Conference. \n\nWe thank the support of NSF through NetSE CNS 0911041, ARPA-E through GENI DE-AR0000226, the National Science Council of Taiwan through NSC 103-3113-P-008-001, Southern California Edison, the Los Alamos National Lab and Caltech's Resnick Institute.", "abstract": "This overview paper summarizes the key elements of semidefinite relaxations of the optimal power flow problem, and discusses several open challenges.", "date": "2014-08", "date_type": "published", "publisher": "The Power Systems Computation Conference", "place_of_pub": "Zurich, Switzerland", "pagerange": "1-11", "id_number": "CaltechAUTHORS:20170123-174612725", "isbn": "978-83-935801-3-2", "book_title": "2014 Power Systems Computation Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170123-174612725", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF NetSE", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 103-3113-P-008-001" }, { "agency": "Southern California Edison" }, { "agency": "Los Alamos National Laboratory (LANL)" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/PSCC.2014.7038373", "pub_year": "2014", "author_list": "Gan, Lingwen and Low, Steven H." }, { "id": "https://authors.library.caltech.edu/records/1fcqw-beg37", "eprint_id": 80127, "eprint_status": "archive", "datestamp": "2023-08-20 02:21:52", "lastmod": "2026-04-06 00:01:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gan-Lingwen", "name": { "family": "Gan", "given": "Lingwen" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Convex relaxations and linear approximation for optimal power flow in multiphase radial networks", "ispublished": "unpub", "full_text_status": "public", "keywords": "Silicon, Linear approximation, Standards, Programming, Numerical stability, Load flow, Computational modeling", "note": "\u00a9 2014 IEEE. \n\nPaper submitted to Power Systems Computation Conference, August 18-22, 2014, Wroclaw, Poland, organized by Power Systems Computation Conference and Wroclaw University of Technology. \n\nThis work was supported by NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California Edison, National Science Council of Taiwan, R.O.C, grant NSC 101-3113-P-008-001, and Caltech's Resnick Institute.\n\nSubmitted - 1406.3054.pdf
", "abstract": "Distribution networks are usually multiphase and radial. To facilitate power flow computation and optimization, two semidefinite programming (SDP) relaxations of the optimal power flow problem and a linear approximation of the power flow are proposed. We prove that the first SDP relaxation is exact if and only if the second one is exact. Case studies show that the second SDP relaxation is numerically exact and that the linear approximation obtains voltages within 0.0016 per unit of their true values for the IEEE 13, 34, 37, 123-bus networks and a real-world 2065-bus network.", "date": "2014-08", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-9", "id_number": "CaltechAUTHORS:20170810-114020714", "isbn": "978-83-935801-3-2", "book_title": "2014 Power Systems Computation Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170810-114020714", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/PSCC.2014.7038399", "primary_object": { "basename": "1406.3054.pdf", "url": "https://authors.library.caltech.edu/records/1fcqw-beg37/files/1406.3054.pdf" }, "pub_year": "2014", "author_list": "Gan, Lingwen and Low, Steven H." }, { "id": "https://authors.library.caltech.edu/records/aptaj-dkg70", "eprint_id": 41910, "eprint_status": "archive", "datestamp": "2023-08-20 01:32:00", "lastmod": "2026-04-06 00:20:37", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Smith-M-A", "name": { "family": "Smith", "given": "Matthew A." } }, { "id": "Arnold-F-H", "name": { "family": "Arnold", "given": "Frances H." }, "orcid": "0000-0002-4027-364X" } ] }, "title": "Designing libraries of chimeric proteins using SCHEMA recombination and RASPP", "ispublished": "unpub", "full_text_status": "public", "keywords": "Protein engineering Homologous recombination SCHEMA RASPP Chimeragenesis", "note": "\u00a9 2014 Springer. \n\nThe authors acknowledge funding from the Institute for Collaborative Biotechnologies through grant W911NF-09-D-0001 from the U.S. Army Research Office and The National Central University,Taiwan, through a Cooperative Agreement for Energy Research Collaboration. MAS is supported by a Resnick Sustainability Institute fellowship.\n\nSubmitted - SCHEMA_MIMB.pdf
", "abstract": "SCHEMA is a method for designing libraries of novel proteins by recombination of homologous sequences. The goal is to maximize the number of folded proteins while simultaneously generating significant sequence diversity. Here, we use the RASPP algorithm to identify optimal SCHEMA designs for shuffling contiguous elements of sequence. To exemplify the method, SCHEMA is used to recombine five fungal cellobiohydrolases (CBH1s) to produce a library of more than 390,000 novel CBH1 sequences.", "date": "2014-06-27", "date_type": "published", "publisher": "Humana Press", "place_of_pub": "New York, NY", "pagerange": "335-343", "id_number": "CaltechAUTHORS:20131015-081653940", "isbn": "978-1-4939-1052-6", "book_title": "Directed Evolution Library Creation: Methods and Protocols", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131015-081653940", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-09-D-001" }, { "agency": "National Central University (Taiwan)" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "contributors": { "items": [ { "id": "Gillam-E-M-J", "name": { "family": "Gillam", "given": "Elizabeth M. J." } }, { "id": "Copp-J-N", "name": { "family": "Copp", "given": "Janine N." } }, { "id": "Ackerley-D", "name": { "family": "Ackerley", "given": "David" } } ] }, "doi": "10.1007/978-1-4939-1053-3_22", "primary_object": { "basename": "SCHEMA_MIMB.pdf", "url": "https://authors.library.caltech.edu/records/aptaj-dkg70/files/SCHEMA_MIMB.pdf" }, "pub_year": "2014", "author_list": "Smith, Matthew A. and Arnold, Frances H." }, { "id": "https://authors.library.caltech.edu/records/rs6m2-1rn35", "eprint_id": 89037, "eprint_status": "archive", "datestamp": "2023-08-22 13:01:00", "lastmod": "2026-04-05 17:17:44", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Smith-M-A", "name": { "family": "Smith", "given": "Matthew A." } }, { "id": "Arnold-F-H", "name": { "family": "Arnold", "given": "Frances H." }, "orcid": "0000-0002-4027-364X" } ] }, "title": "Noncontiguous SCHEMA Protein Recombination", "ispublished": "unpub", "full_text_status": "public", "keywords": "Protein engineering; Homologous recombination; SCHEMA; Noncontiguous recombination; NCR; Chimeragenesis", "note": "\u00a9 Springer Science+Business Media New York 2014. \n\nThe authors acknowledge funding from the Institute for Collaborative Biotechnologies through grant W911NF-09-D-0001 from the US Army Research Office and the National Central University, Taiwan, through a Cooperative Agreement for Energy Research Collaboration. M.A.S. is supported by a Resnick Sustainability Institute fellowship.", "abstract": "SCHEMA is a method of designing protein recombination libraries that contain a large fraction of functional proteins with a high degree of mutational diversity. In the previous chapter, we illustrated the method for designing libraries by swapping contiguous sequence elements. Here, we introduce the NCR (\"noncontiguous recombination\") algorithm to identify optimal designs for swapping elements that are contiguous in the 3-D structure but not necessarily in the primary sequence. To exemplify the method, NCR is used to recombine three fungal cellobiohydrolases (CBH1s) to produce a library containing more than 500,000 novel chimeric sequences.", "date": "2014-06-27", "date_type": "published", "publisher": "Humana Press", "place_of_pub": "New York, NY", "pagerange": "345-352", "id_number": "CaltechAUTHORS:20180822-140726128", "isbn": "9781493910526", "book_title": "Directed Evolution Library Creation: Methods and Protocols", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180822-140726128", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Army Research Office (ARO)", "grant_number": "W911NF-09-D-0001" }, { "agency": "National Central University (Taiwan)" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "contributors": { "items": [ { "id": "Gillam-M-J", "name": { "family": "Gillam", "given": "M. J." } }, { "id": "Copp-J-N", "name": { "family": "Copp", "given": "Janine N." } }, { "id": "Ackerley-D", "name": { "family": "Ackerley", "given": "David" } } ] }, "doi": "10.1007/978-1-4939-1053-3_23", "pub_year": "2014", "author_list": "Smith, Matthew A. and Arnold, Frances H." }, { "id": "https://authors.library.caltech.edu/records/d0ekx-s4y27", "eprint_id": 55126, "eprint_status": "archive", "datestamp": "2023-08-19 22:25:44", "lastmod": "2026-04-09 20:05:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Thrampoulidis-C", "name": { "family": "Thrampoulidis", "given": "Christos" }, "orcid": "0000-0001-9053-9365" }, { "id": "Bose-Subhonmesh", "name": { "family": "Bose", "given": "Subhonmesh" }, "orcid": "0000-0002-3445-4479" }, { "id": "Hassibi-B", "name": { "family": "Hassibi", "given": "Babak" }, "orcid": "0000-0002-1375-5838" } ] }, "title": "On the distribution of energy storage in electricity grids", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 IEEE.\n\nThis work was supported in part by NSF under\ngrants CCF-0729203, CNS-0932428 and CCF-1018927, NetSE grant CNS 0911041, Office of Naval Research MURI grant N00014-08-1-0747, Caltech Lee Center for Adv. Net., ARPA-E grant DE-AR0000226, Southern Cali. Edison, Nat. Sc. Council of Taiwan, R.O.C. grant NSC 101-3113-P-008-001, Resnick Inst., Okawa Foundation and Andreas Mentzelopoulos Scholarships for the Univ. of Patras.", "abstract": "Distributed energy storage is a promising emerging technology for smart grid. In this paper, we address the question of optimally placing and sizing distributed storage resources in a network to minimize the cost of generation given a budget of available storage. For a non-decreasing convex generation cost, we prove that it is always optimal to place zero storage at generator buses that connect to rest of the grid via single links, regardless of demand profiles and network parameters. Hence, this defines a robust investment strategy for network planners. Besides, for a star network where the center is a generator bus and the other nodes are demand buses, we show that it is optimal not to place storage resources at the generator bus for small enough and large enough storage budget.", "date": "2013-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "7590-7596", "id_number": "CaltechAUTHORS:20150224-071641038", "isbn": "978-1-4673-5714-2", "book_title": "IEEE 52nd Annual Conference on Decision and Control (CDC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150224-071641038", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CCF-0729203" }, { "agency": "NSF", "grant_number": "CNS-0932428" }, { "agency": "NSF", "grant_number": "CCF-1018927" }, { "agency": "NSF NetSE", "grant_number": "CNS 0911041" }, { "agency": "Office of Naval Research (ONR)", "grant_number": "N00014-08-1-0747" }, { "agency": "Caltech Lee Center for Advanced Networking" }, { "agency": "Department of Energy (DOE) ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council of Taiwan" }, { "agency": "R.O.C.", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Institute" }, { "agency": "Okawa Foundation" }, { "agency": "Andreas Mentzelopoulos Scholarships for the University of Patras" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2013.6761094", "pub_year": "2013", "author_list": "Thrampoulidis, Christos; Bose, Subhonmesh; et al." }, { "id": "https://authors.library.caltech.edu/records/cqytx-nhs12", "eprint_id": 80185, "eprint_status": "archive", "datestamp": "2023-08-19 22:27:01", "lastmod": "2026-04-09 20:14:03", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Peng-Qiuyu", "name": { "family": "Peng", "given": "Qiuyu" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Optimal branch exchange for feeder reconfiguration in distribution networks", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Substations, Load modeling, Network topology, Topology, Optimization, Mathematical model, Integrated circuit modeling", "note": "\u00a9 2013 IEEE. \n\nThis work was supported by NSF NetSE grant CNS 091104, ARPA-E\ngrant DE-AR0000226, Southern California Edison, National Science Council of Taiwan, R.O.C. grant NSC 101-3113-P-008-001 and Resnick Institute.", "abstract": "The feeder reconfiguration problem chooses the on/off status of the switches in a distribution network in order to minimize a certain cost such as power loss. It is a mixed integer nonlinear program and hence hard to solve. A popular heuristic search consists of repeated application of branch exchange, where some loads are transferred from one feeder to another feeder while maintaining the radial structure of the network, until no load transfer can further reduce the cost. Optimizing each branch exchange step is itself a mixed integer nonlinear program. In this paper we propose an efficient algorithm for optimizing a branch exchange step. It uses an AC power flow model and is based on the recently developed convex relaxation of optimal power flow. We provide a bound on the gap between the optimal cost and that of our solution. We prove that our algorithm is optimal when the voltage magnitudes are the same at all buses. We illustrate the effectiveness of our algorithm through the simulation of real-world distribution feeders.", "date": "2013-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2960-2965", "id_number": "CaltechAUTHORS:20170810-131659189", "isbn": "978-1-4673-5714-2", "book_title": "2013 IEEE 52nd Annual Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170810-131659189", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-091104" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2013.6760333", "pub_year": "2013", "author_list": "Peng, Qiuyu and Low, Steven H." }, { "id": "https://authors.library.caltech.edu/records/16qrb-p1t76", "eprint_id": 80123, "eprint_status": "archive", "datestamp": "2023-08-19 22:26:53", "lastmod": "2026-04-09 17:26:50", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gan-Lingwen", "name": { "family": "Gan", "given": "Lingwen" } }, { "id": "Li-Na", "name": { "family": "Li", "given": "Na" } }, { "id": "Topcu-U", "name": { "family": "Topcu", "given": "Ufuk" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Optimal power flow in tree networks", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Silicon, Reactive power, Linear approximation, Capacitors, Distributed power generation, Upper bound, Generators", "note": "\u00a9 2013 IEEE. \n\nThis work was supported by NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California Edison, National Science Council of Taiwan, R.O.C, grant NSC 101-3113-P-008-001, Resnick Institute, Okawa Foundation, NSF CNS 1312390, DoE grant DE-EE000289, and AFOSR award number FA9550-12-1-0302.", "abstract": "The optimal power flow (OPF) problem seeks to control power generation/demand to optimize certain objectives such as minimizing the generation cost or power loss. It is becoming increasingly important for tree distribution networks due to the emerging distributed generation and controllable loads. The OPF problem is nonconvex. We prove that after modifying the OPF problem, its global optimum can be recovered via a second-order cone programming (SOCP) relaxation for tree networks, under a condition that can be checked in advance. Empirical studies justify that the modification is \"small\", and that the condition holds, for the IEEE 13-bus network and two real-world networks.", "date": "2013-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "2313-2318", "id_number": "CaltechAUTHORS:20170810-113418095", "isbn": "978-1-4673-5714-2", "book_title": "52nd IEEE Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170810-113418095", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" }, { "agency": "NSF", "grant_number": "CNS-1312390" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-EE0002890" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0302" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2013.6760226", "pub_year": "2013", "author_list": "Gan, Lingwen; Li, Na; et al." }, { "id": "https://authors.library.caltech.edu/records/dps39-gck77", "eprint_id": 80122, "eprint_status": "archive", "datestamp": "2023-08-19 22:26:45", "lastmod": "2026-04-09 22:00:01", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farivar-M", "name": { "family": "Farivar", "given": "Masoud" } }, { "id": "Chen-Lijun", "name": { "family": "Chen", "given": "Lijun" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven" }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Equilibrium and dynamics of local voltage control in distribution systems", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Reactive power, Voltage control, Optimization, Mathematical model, Inverters, Heuristic algorithms, Vectors", "note": "\u00a9 2013 IEEE. \n\nThis work was supported by Resnick Sustainbility Institute at Caltech, Advanced Technology Division of Southern California Edison, NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, National Science Council of Taiwan, R.O.C, grant NSC 101-3113-P-008-001.", "abstract": "We consider a class of local volt/var control schemes where the control decision on the reactive power at a bus depends only on the local bus voltage. These local algorithms form a feedback dynamical system and collectively determine the bus voltages of a power network. We show that the dynamical system has a unique equilibrium by interpreting the dynamics as a distributed algorithm for solving a certain convex optimization problem whose unique optimal point is the system equilibrium. Moreover, the objective function serves as a Lyapunov function implying global asymptotic stability of the equilibrium. The optimization based model does not only provide a way to characterize the equilibrium, but also suggests a principled way to engineer the control. We apply the results to study the parameter setting for the inverter-based volt/var control in the proposed IEEE 1547.8 standard.", "date": "2013-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "4329-4334", "id_number": "CaltechAUTHORS:20170810-113209963", "isbn": "978-1-4673-5714-2", "book_title": "52nd IEEE Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170810-113209963", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Resnick Sustainability Institute" }, { "agency": "Southern California Edison" }, { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2013.6760555", "pub_year": "2013", "author_list": "Farivar, Masoud; Chen, Lijun; et al." }, { "id": "https://authors.library.caltech.edu/records/d2cwy-kk883", "eprint_id": 44849, "eprint_status": "archive", "datestamp": "2023-08-19 20:37:49", "lastmod": "2026-04-09 16:11:28", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Thrampoulidis-C", "name": { "family": "Thrampoulidis", "given": "Christos" }, "orcid": "0000-0001-9053-9365" }, { "id": "Bose-Subhonmesh", "name": { "family": "Bose", "given": "Subhonmesh" }, "orcid": "0000-0002-3445-4479" }, { "id": "Hassibi-B", "name": { "family": "Hassibi", "given": "Babak" }, "orcid": "0000-0002-1375-5838" } ] }, "title": "Optimal Large-scale Storage Placement in Single Generator Single Load Networks", "ispublished": "unpub", "full_text_status": "public", "keywords": "Electricity storage, load shifting, storage placement", "note": "\u00a9 2013 IEEE. This work was supported in part by NSF under grants CCF-0729203, CNS-0932428 and CCF-1018927, NetSE grant CNS 0911041, Office of Naval Research MURI grant N00014-08-1-0747, Caltech Lee Center for Adv. Net.,\nARPA-E grant DE-AR0000226, Southern Cali. Edison, Nat. Sc. Council of Taiwan, R.O.C. grant NSC 101-3113-P-008-001, Resnick Inst., Okawa Foundation and Andreas Mentzelopoulos Scholarships for the Univ. of Patras. The authors gratefully acknowledge Prof. K. Mani Chandy\nat California Institute of Technology and Mr. Paul DeMartini\nfrom Resnick Institute for their helpful comments.\n\nSubmitted - Optimal_20Large-scale_20Storage_20Placement.pdf
", "abstract": "Large-scale storage will play an increasingly important role in future power grids. As a result, how to optimally place storage in such networks, is an important investment problem. Furthermore, since the allocation of storage resources is static, i.e., it is not feasible to move storage around in a dynamic fashion, it is important to derive optimal such allocations that are robust to the values of the load profiles and other network parameters, such as the line flow constraints. For a single generator single load network, and for a cost of generation that is quadratic in the generation power, we show that, for any given amount of storage resources, placing storage at the demand node is always optimal. This result is true regardless of the demand profile and flow constraints, and therefore is robust. As a byproduct of this result, for a fixed demand profile, we characterize the dependence of the optimal production cost on the flow constraints and on the available storage resources.", "date": "2013-07", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-5", "id_number": "CaltechAUTHORS:20140410-095815023", "isbn": "978-1-4799-1303-9", "book_title": "2013 Power and Energy Society General Meeting (PES)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140410-095815023", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CCF-0729203" }, { "agency": "NSF", "grant_number": "CNS-0932428" }, { "agency": "NSF", "grant_number": "CCF-1018927" }, { "agency": "NetSE", "grant_number": "CNS 0911041" }, { "agency": "Office of Naval Research (ONR) MURI", "grant_number": "N00014-08-1-0747" }, { "agency": "Caltech Lee Center for Advanced Networking" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council of Taiwan", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Institute" }, { "agency": "Okawa Foundation" }, { "agency": "University of Patras Andreas Mentzelopoulos Scholarships" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/PESMG.2013.6672589", "primary_object": { "basename": "Optimal_20Large-scale_20Storage_20Placement.pdf", "url": "https://authors.library.caltech.edu/records/d2cwy-kk883/files/Optimal_20Large-scale_20Storage_20Placement.pdf" }, "pub_year": "2013", "author_list": "Thrampoulidis, Christos; Bose, Subhonmesh; et al." }, { "id": "https://authors.library.caltech.edu/records/d9hmh-bz679", "eprint_id": 49830, "eprint_status": "archive", "datestamp": "2023-08-19 20:16:33", "lastmod": "2026-04-09 21:51:35", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Kosten-E-D", "name": { "family": "Kosten", "given": "Emily D." } }, { "id": "Lloyd-J-R", "name": { "family": "Lloyd", "given": "John" } }, { "id": "Warmann-E-C", "name": { "family": "Warmann", "given": "Emily" }, "orcid": "0000-0002-2810-4608" }, { "id": "Atwater-H-A", "name": { "family": "Atwater", "given": "Harry A." }, "orcid": "0000-0001-9435-0201" } ] }, "title": "Spectrum splitting photovoltaics: Light trapping filtered concentrator for ultrahigh photovoltaic efficiency", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "photovoltaic cells, optical filters, geometrical optics, III-V semiconductor materials, photonic crystals", "note": "\u00a9 2013 IEEE.\n\nThis project was supported by the Dow Chemical Company\nand the DOE 'Light-Material Interactions in Energy\nConversion' Energy Frontier Research Center under grant DESC0001293.\nE. Kosten is supported by the Resnick Institute\nGraduate Fellowship. The authors wish to thank M. Escarra,\nC. Eisler, S. Darbe, and C. Flowers for helpful discussions and\ncomments on the manuscript.", "abstract": "We investigate a spectrum splitting approach where light is trapped in a textured dielectric slab and coupled into underlying solar cells of different bandgaps through filters. We describe a specific design featuring an SiO_2 textured slab coated with angle restricting incoupling elements and four underlying dual junction subcells, based on light trapping and efficiency considerations. We then design a full set of four omnidirectional filters based on aperiodic dielectric multilayer films to split the light entering each subcell into spectral bands tuned to the cell bandgaps. Based on the calculated filter performance, we estimate a receiver efficiency of 45% with this initial design.", "date": "2013-06", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3053-3057", "id_number": "CaltechAUTHORS:20140918-140006156", "isbn": "978-1-4799-3299-3", "book_title": "IEEE 39th Photovoltaic Specialists Conference", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140918-140006156", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Dow Chemical Company" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-SC0001293" }, { "agency": "Resnick Sustainability Institute" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/PVSC.2013.6745105", "pub_year": "2013", "author_list": "Kosten, Emily D.; Lloyd, John; et al." }, { "id": "https://authors.library.caltech.edu/records/m4gqe-7j072", "eprint_id": 71479, "eprint_status": "archive", "datestamp": "2023-08-19 19:49:04", "lastmod": "2026-04-09 15:34:00", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gan-Lingwen", "name": { "family": "Gan", "given": "Lingwen" } }, { "id": "Wierman-A", "name": { "family": "Wierman", "given": "Adam" } }, { "id": "Topcu-U", "name": { "family": "Topcu", "given": "Ufuk" } }, { "id": "Chen-Niangjun", "name": { "family": "Chen", "given": "Niangjun" }, "orcid": "0000-0002-2289-9737" }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Real-time deferrable load control: handling the uncertainties of renewable generation", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "smart grid, deferrable load control, demand response, model predictive control", "note": "\u00a9 2013 ACM. \n\nThis work was supported by NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California Edison, National Science Council of Taiwan, R.O.C, grant NSC 101-3113-P-008-001, Resnick Institute, Okawa Foundation, NSF CNS 1312390, NSF grant CNS 0846025, and DoE grant DE-EE000289.", "abstract": "Real-time demand response is essential for handling the uncertainties of renewable generation. Traditionally, demand response has been focused on large industrial and commercial loads, however it is expected that a large number of small residential loads such as air conditioners, dish washers, and electric vehicles will also participate in the coming years. The electricity consumption of these smaller loads, which we call deferrable loads, can be shifted over time, and thus be used (in aggregate) to compensate for the random fluctuations in renewable generation. In this paper, we propose a real-time distributed deferrable load control algorithm to reduce the variance of aggregate load (load minus renewable generation) by shifting the power consumption of deferrable loads to periods with high renewable generation. At every time step, the algorithm minimizes the expected variance to go with updated predictions. We prove that suboptimality of the algorithm vanishes as time horizon expands. Further, we evaluate the algorithm via trace-based simulations.", "date": "2013-05", "date_type": "published", "publisher": "ACM", "place_of_pub": "New York, NY", "pagerange": "113-124", "id_number": "CaltechAUTHORS:20161025-161438752", "isbn": "978-1-4503-2052-8", "book_title": "e-Energy '13 Proceedings of the fourth international conference on Future energy systems", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161025-161438752", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF NetSE", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" }, { "agency": "NSF", "grant_number": "CNS-1312390" }, { "agency": "NSF", "grant_number": "CNS-0846025" }, { "agency": "Department of Energy (DOE)", "grant_number": "DE-EE0002890" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "contributors": { "items": [ { "id": "Culler-D", "name": { "family": "Culler", "given": "David" } }, { "id": "Rosenberg-C", "name": { "family": "Rosenberg", "given": "Catherine" } } ] }, "doi": "10.1145/2487166.2487179", "pub_year": "2013", "author_list": "Gan, Lingwen; Wierman, Adam; et al." }, { "id": "https://authors.library.caltech.edu/records/14kbw-vmr35", "eprint_id": 41846, "eprint_status": "archive", "datestamp": "2023-08-22 08:37:05", "lastmod": "2026-04-09 17:20:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Taft-J", "name": { "family": "Taft", "given": "Jeffrey" } }, { "id": "De-Martini-P", "name": { "family": "De Martini", "given": "Paul" } } ] }, "title": "Ultra-large scale control architecture", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "controls; architecture; distributed resources; markets", "note": "\u00a9 Copyright 2013 IEEE.", "abstract": "Electric power grid complexity is growing rapidly as we attempt to support technical, business, and societal goals for which power grids were not originally designed. To ensure grid stability and have the ability to remain reliable under highly dynamic destabilizing conditions requires that grid control systems evolve in ways that address transformational changes and the resultant operational problems. Ultra-large scale power system control architecture - a macro architecture for grid control that handles multi-objective, multi-constraint problems in a framework that can support coordinated control across utility organizational boundaries and, potentially, prosumer premises. The keys to this approach are three-fold: rectify the macro-structure of grid control to eliminate the emerging chaos; introduce two-axis distributed control; apply multi-level hierarchical optimization tools to grid control design. This paper describes emerging issues in grid control and provides reasons why the present path of grid control evolution is problematic and presents an ultra-large scale architecture for grid control that can solve today's problems and those expected over the next 30 years.", "date": "2013-02", "date_type": "published", "publisher": "IEEE", "pagerange": "1-6", "id_number": "CaltechAUTHORS:20131009-165511027", "isbn": "978-1-4673-4894-2", "book_title": "Innovative Smart Grid Technologies (ISGT), 2013", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131009-165511027", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/ISGT.2013.6497906", "pub_year": "2013", "author_list": "Taft, Jeffrey and De Martini, Paul" }, { "id": "https://authors.library.caltech.edu/records/a5yj9-kj319", "eprint_id": 39943, "eprint_status": "archive", "datestamp": "2023-08-19 13:41:51", "lastmod": "2023-10-24 17:19:38", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gan-Lingwen", "name": { "family": "Gan", "given": "Lingwen" } }, { "id": "Jiang-Libin", "name": { "family": "Jiang", "given": "Libin" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven" }, "orcid": "0000-0001-6476-3048" }, { "id": "Topcu-U", "name": { "family": "Topcu", "given": "Ufuk" } }, { "id": "Zhao-Changhong", "name": { "family": "Zhao", "given": "Changhong" }, "orcid": "0000-0003-0539-8591" } ] }, "title": "Some Problems in Demand Side Management", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2013 IEEE.\n\nThis work is supported by NSF NetSE grant CNS 0911041, ARPA-E grant\nDE-AR0000226, Southern California Edison, National Science Council of\nTaiwan, R.O.C. grant NSC 101-3113-P-008-001, Caltech's Resnick Institute\nand the Okawa Foundation.", "abstract": "We present a sample of problems in demand side\nmanagement in future power systems and illustrate how they\ncan be solved in a distributed manner using local information.\nFirst, we consider a set of users served by a single load-serving\nentity (LSE). The LSE procures capacity a day ahead. When\nrandom renewable energy is realized at delivery time, it manages\nuser load through real-time demand response and purchases\nbalancing power on the spot market to meet the aggregate\ndemand. Hence optimal supply procurement by the LSE and the\nconsumption decisions by the users must be coordinated over two\ntimescales, a day ahead and in real time, in the presence of supply\nuncertainty. Moreover, they must be computed jointly by the\nLSE and the users since the necessary information is distributed\namong them. We present distributed algorithms to maximize\nexpected social welfare. Instead of social welfare, the second\nproblem is to coordinate electric vehicle charging to fill the valleys\nin aggregate electric demand profile, or track a given desired\nprofile. We present synchronous and asynchronous algorithms\nand prove their convergence. Finally, we show how loads can\nuse locally measured frequency deviations to adapt in real time\ntheir demand in response to a shortfall in supply. We design\ndecentralized demand response mechanism that, together with\nthe swing equation of the generators, jointly maximize disutility\nof demand rationing, in a decentralized manner.", "date": "2012-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1-6", "id_number": "CaltechAUTHORS:20130815-100621563", "isbn": "978-1-4673-4863-8", "book_title": "2012 Asia-Pacific Signal & Information Processing Association Annual Summit and Conference (APSIPA ASC)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130815-100621563", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF NetSE", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "pub_year": "2012", "author_list": "Gan, Lingwen; Jiang, Libin; et al." }, { "id": "https://authors.library.caltech.edu/records/f03t1-zt633", "eprint_id": 43108, "eprint_status": "archive", "datestamp": "2023-08-19 13:42:35", "lastmod": "2026-04-10 01:07:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Farivar-M", "name": { "family": "Farivar", "given": "Masoud" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Branch flow model: Relaxations and convexification", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE.\nWe are grateful to Mani Chandy, Lingwen Gan, and Javad\nLavaei of Caltech, and Christopher Clarke, Michael Montoya,\nand Robert Sherick of the Southern California Edison\nfor helpful discussions. We acknowledge the support of\nthe Resnick Sustainability Institute at Caltech, NSF through\nNetSE grant CNS 0911041, DoE's ARPA-E through grant DE-AR0000226, the National Science Council of Taiwan (R.\nO. C.) through grant NSC 101-3113-P-008-001, Southern\nCalifornia Edison, Cisco, and the Okawa Foundation.", "abstract": "We propose a branch flow model for the analysis and optimization of mesh as well as radial networks. The model leads to a new approach to solving optimal power flow (OPF) problems that consists of two relaxation steps. The first step eliminates the voltage and current angles and the second step approximates the resulting problem by a conic program that can be solved efficiently. For radial networks, we prove that both relaxation steps are always exact, provided there are no upper bounds on loads. For mesh networks, the conic relaxation is always exact and we characterize when the angle relaxation may fail. We propose a simple method to convexify a mesh network using phase shifters so that both relaxation steps are always exact and OPF for the convexified network can always be solved efficiently for a globally optimal solution. We prove that convexification requires phase shifters only outside a spanning tree of the network graph and their placement depends only on network topology, not on power flows, generation, loads, or operating constraints. Since power networks are sparse, the number of required phase shifters may be relatively small.", "date": "2012-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "3672-3679", "id_number": "CaltechAUTHORS:20131220-084709018", "isbn": "978-1-4673-2065-8", "book_title": "51st IEEE Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131220-084709018", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Resnick Sustainability Institute" }, { "agency": "NSF NetSE", "grant_number": "CNS 0911041" }, { "agency": "Department of Energy (DOE) ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "National Science Council of Taiwan", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Southern California Edison" }, { "agency": "Cisco" }, { "agency": "Okawa Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "13288515", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2012.6425870", "pub_year": "2012", "author_list": "Farivar, Masoud and Low, Steven H." }, { "id": "https://authors.library.caltech.edu/records/qtmgt-jpt39", "eprint_id": 39659, "eprint_status": "archive", "datestamp": "2023-08-19 13:41:44", "lastmod": "2026-04-10 14:25:04", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Na", "name": { "family": "Li", "given": "Na" } }, { "id": "Gan-Lingwen", "name": { "family": "Gan", "given": "Lingwen" } }, { "id": "Chen-Lijun", "name": { "family": "Chen", "given": "Lijun" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "An optimization-based demand response in radial distribution networks", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. \n\nThis work is supported by NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California Edison, National Science Council of Taiwan, R.O.C. grant, NSC 101-3113-P-008-001, the Caltech Resnick Institute, and the Okawa Foundation.", "abstract": "Demand response has recently become a topic of active research. Most of work however considers only the balance between aggregate load and supply, and abstracts away the underlying power network and the associated power flow constraints and operating constraints. In this paper, we study demand response in a radial distribution network, by formulating it as an optimal power flow problem that maximizes the aggregate user utilities and minimizes the power line losses, subject to the power flow constraints and operating constraints. As the resulting problem is non-convex and difficult to solve, we propose a convex relaxation that is usually exact for the real-world distribution circuits. We then propose a distributed algorithm for the load-serving entity to set the price signal to coordinate the users' demand response so as to achieve the optimum. Numerical examples show that the proposed algorithm converges fast for real-world distribution systems.", "date": "2012-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1474-1479", "id_number": "CaltechAUTHORS:20130730-133244823", "isbn": "978-1-4673-4941-3", "book_title": "2012 IEEE Globecom Workshops", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130730-133244823", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/GLOCOMW.2012.6477803", "pub_year": "2012", "author_list": "Li, Na; Gan, Lingwen; et al." }, { "id": "https://authors.library.caltech.edu/records/xqngg-p9h45", "eprint_id": 43112, "eprint_status": "archive", "datestamp": "2023-08-19 13:42:51", "lastmod": "2026-04-10 01:08:56", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gan-Lingwen", "name": { "family": "Gan", "given": "Lingwen" } }, { "id": "Li-Na", "name": { "family": "Li", "given": "Na" } }, { "id": "Topcu-U", "name": { "family": "Topcu", "given": "Ufuk" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven" }, "orcid": "0000-0001-6476-3048" } ] }, "title": "On the exactness of convex relaxation for optimal power flow in tree networks", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. \n\nThis work was supported by Bell Labs of Alcatel-Lucent, NSF NetSE\ngrant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California\nEdison, National Science Council of Taiwan, R.O.C, grant NSC 101-3113-P-008-001, Resnick Institute, Okawa Foundation, Boeing Corporation, Cisco, and AFOSR award number FA9550-12-1-0302.", "abstract": "The optimal power flow problem is nonconvex, and a convex relaxation has been proposed to solve it. We prove that the relaxation is exact, if there are no upper bounds on the voltage, and any one of some conditions holds. One of these conditions requires that there is no reverse real power flow, and that the resistance to reactance ratio is non-decreasing as transmission lines spread out from the substation to the branch buses. This condition is likely to hold if there are no distributed generators. Besides, avoiding reverse real power flow can be used as rule of thumb for placing distributed generators.", "date": "2012-12", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "465-471", "id_number": "CaltechAUTHORS:20131220-094526108", "isbn": "978-1-4673-2065-8", "book_title": "51st IEEE Conference on Decision and Control", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131220-094526108", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Bell Labs of Alcatel-Lucent" }, { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" }, { "agency": "Boeing Corporation" }, { "agency": "Cisco" }, { "agency": "Air Force Office of Scientific Research (AFOSR)", "grant_number": "FA9550-12-1-0302" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/CDC.2012.6426045", "pub_year": "2012", "author_list": "Gan, Lingwen; Li, Na; et al." }, { "id": "https://authors.library.caltech.edu/records/e6qj1-29t23", "eprint_id": 40933, "eprint_status": "archive", "datestamp": "2023-08-19 13:22:31", "lastmod": "2026-04-10 01:25:23", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Na", "name": { "family": "Li", "given": "Na" } }, { "id": "Chen-Lijun", "name": { "family": "Chen", "given": "Lijun" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Exact Convex Relaxation of OPF for Radial Networks using Branch Flow Model", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. \n\nThe authors would like to acknowledge Lingwen Gan for his insightful discussions on this topic. This work is supported by NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California Edison, National Science Council of Taiwan, R.O.C. grant, NSC 101-3113-P-008-001, the Caltech Resnick Institute, and the Okawa Foundation.", "abstract": "The optimal power flow (OPF) problem is generally nonconvex. Recently a second-order cone relaxation for OPF has been proposed using the branch flow model. In this paper, we provide sufficient conditions under which the relaxation is exact, and demonstrate that these conditions hold for a wide class of practical power distribution systems.", "date": "2012-11", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "7-12", "id_number": "CaltechAUTHORS:20130826-134301716", "isbn": "978-1-4673-0910-3", "book_title": "IEEE Third International Conference on Smart Grid Communications", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130826-134301716", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/SmartGridComm.2012.6485951", "pub_year": "2012", "author_list": "Li, Na; Chen, Lijun; et al." }, { "id": "https://authors.library.caltech.edu/records/8v9tq-x2v45", "eprint_id": 39722, "eprint_status": "archive", "datestamp": "2023-08-19 13:22:20", "lastmod": "2026-04-10 01:58:43", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Li-Na", "name": { "family": "Li", "given": "Na" } }, { "id": "Chen-Lijun", "name": { "family": "Chen", "given": "Lijun" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Demand response in radial distribution networks: Distributed algorithm", "ispublished": "unpub", "full_text_status": "restricted", "keywords": "Demand response, Distributed algorithm, Branch flow model, Optimal power flow problem, Distribution networks", "note": "\u00a9 2012 IEEE. \n\nThis work is supported by NSF NetSE grant CNS 0911041, ARPA-E grant DE-AR0000226, Southern California Edison, National Science Council of Taiwan, R.O.C. grant, NSC 101-3113-P-008-001, the Caltech Resnick Institute, and the Okawa Foundation.", "abstract": "Demand response has recently become a topic of active research. Most of work however considers only the balance between aggregate load and supply, and abstracts away the underlying power network. In this paper, we study demand response in a radial distribution network, by formulating it as an optimal power flow problem that maximizes the aggregate user utilities and minimizes the supply cost and the power line losses, subject to the power flow constraints and operating constraints. We propose a fully distributed algorithm for the users to coordinate their demand response decisions through local communication with their neighbors so as to achieve the optimum. Numerical examples with the real-world distribution circuits are provided to complement our theoretical analysis.", "date": "2012-11", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1549-1553", "id_number": "CaltechAUTHORS:20130802-082120272", "isbn": "978-1-4673-5050-1", "book_title": "2012 Conference Record of the Forty Sixth Asilomar Conference on Signals, Systems and Computers (ASILOMAR)", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130802-082120272", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/ACSSC.2012.6489288", "pub_year": "2012", "author_list": "Li, Na; Chen, Lijun; et al." }, { "id": "https://authors.library.caltech.edu/records/w6w9y-cfd86", "eprint_id": 40970, "eprint_status": "archive", "datestamp": "2023-08-19 13:22:46", "lastmod": "2026-04-10 01:05:09", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zhao-Changhong", "name": { "family": "Zhao", "given": "Changhong" }, "orcid": "0000-0003-0539-8591" }, { "id": "Topcu-U", "name": { "family": "Topcu", "given": "Ufuk" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven" }, "orcid": "0000-0001-6476-3048" } ] }, "title": "Swing dynamics as primal-dual algorithm for optimal load control", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE.\n\nThis work is supported by NSF NetSE grant CNS 0911041,\nARPA-E grant DE-AR0000226, Southern California Edison,\nNational Science Council of Taiwan, R.O.C. grant NSC 101-\n3113-P-008-001, Resnick Institute, and Okawa Foundation.", "abstract": "In electricity transmission networks, loads can provide flexible, fast responsive, and decentralized sources for frequency regulation and generation-demand balancing, complementary to generation control. We consider an optimal load control (OLC) problem in a transmission network, when a disturbance in generation occurs on an arbitrary subset of the buses. In OLC, the frequency-insensitive loads are reduced (or increased) in real-time in a way that balances the generation shortfall (or surplus), resynchronizes the bus frequencies, and minimizes the aggregate disutility of load control. We propose a frequency-based load control mechanism and show that the swing dynamics of the network, together with the proposed mechanism, act as a decentralized primal-dual algorithm to solve OLC. Simulation shows that the proposed mechanism can resynchronize the bus frequencies, balance demand with generation and achieve the optimum of OLC within several seconds after a disturbance in generation. Through simulation, we also compare the performance of the proposed mechanism with automatic generation control (AGC), and discuss the effect of their incorporation.", "date": "2012-11", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "570-575", "id_number": "CaltechAUTHORS:20130828-101518387", "isbn": "978-1-4673-0910-3", "book_title": "IEEE Third International Conference on Smart Grid Communications", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130828-101518387", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF NetSE", "grant_number": "CNS-0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "Southern California Edison" }, { "agency": "National Science Council (Taipei)", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Resnick Sustainability Institute" }, { "agency": "Okawa Foundation" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/SmartGridComm.2012.6486046", "pub_year": "2012", "author_list": "Zhao, Changhong; Topcu, Ufuk; et al." }, { "id": "https://authors.library.caltech.edu/records/rk6zp-gad61", "eprint_id": 39668, "eprint_status": "archive", "datestamp": "2023-08-19 13:02:20", "lastmod": "2026-04-10 13:42:07", "type": "book_section", "metadata_visibility": "show", "creators": { "items": [ { "id": "Subhonmesh-B", "name": { "family": "Subhonmesh", "given": "Bose" } }, { "id": "Low-S-H", "name": { "family": "Low", "given": "Steven H." }, "orcid": "0000-0001-6476-3048" }, { "id": "Chandy-K-M", "name": { "family": "Chandy", "given": "K. Mani" } } ] }, "title": "Equivalence of Branch Flow and Bus Injection Models", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2012 IEEE. We are thankful to Lingwen Gan for helpful discussions. We acknowledge the support of the Resnick Institute at Caltech, National Science Foundation through NetSE grant CNS 0911041, Department of Energy's ARPA-E through grant DE-AR0000226, the National Science Council of Taiwan (R.O. C.) through grant NSC 101-3113-P-008-001, Southern California Edison, Cisco, and the Okawa Foundation.", "abstract": "A branch flow model has recently been proposed for the analysis and optimization of power flows. In this paper we show that the model is equivalent to the more popular bus injection model. Moreover, we prove the equivalence of various relaxations of these two models.", "date": "2012-10", "date_type": "published", "publisher": "IEEE", "place_of_pub": "Piscataway, NJ", "pagerange": "1893-1899", "id_number": "CaltechAUTHORS:20130731-091844876", "isbn": "978-1-4673-4537-8", "book_title": "2012 50th Annual Allerton Conference on Communication, Control, and Computing", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130731-091844876", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Resnick Institute" }, { "agency": "NSF NetSE grant", "grant_number": "CNS 0911041" }, { "agency": "ARPA-E", "grant_number": "DE-AR0000226" }, { "agency": "National Science Council of Taiwan", "grant_number": "NSC 101-3113-P-008-001" }, { "agency": "Southern California Edison" }, { "agency": "Cisco" }, { "agency": "Okawa Foundation" } ] }, "other_numbering_system": { "items": [ { "id": "13400577", "name": "INSPEC Accession Number" } ] }, "local_group": { "items": [ { "id": "Resnick-Sustainability-Institute" } ] }, "doi": "10.1109/Allerton.2012.6483453", "pub_year": "2012", "author_list": "Subhonmesh, Bose; Low, Steven H.; et al." } ]