%0 Journal Article
%J Journal of Regulatory Economics
%D 2011
%T Optimal transmission switching: economic efficiency and market implications
%A Kory W. Hedman
%A Shmuel S. Oren
%A Richard P. O'Neill
%K power system economics
%K RM08-001
%X Traditionally, transmission assets for bulk power flow in the electric grid have been modeled as fixed assets in the short run, except during times of forced outages or maintenance. This traditional view does not permit reconfiguration of the transmission grid by the system operators to improve system performance and economic efficiency. The current push to create a smarter grid has brought to the forefront the possibility of co-optimizing generation along with the network topology by incorporating the control of transmission assets within the economic dispatch formulations. Unfortunately, even though such co-optimization improves the social welfare, it may be incompatible with prevailing market design practices since it can create winners and losers among market participants and it has unpredictable distributional consequences in the energy market and in the financial transmission rights (FTR) market. In this paper, we first provide an overview of recent research on optimal transmission switching, which demonstrates the substantial economic benefit that is possible even while satisfying standard N−1 reliability requirements. We then discuss various market implications resulting from co-optimizing the network topology with generation and we examine how transmission switching may affect locational Marginal Prices (LMPs), i.e., energy prices, and revenue adequacy in the FTR market when FTR settlements are financed by congestion revenues.
%B Journal of Regulatory Economics
%V 40
%P 111 - 140
%8 10/2011
%N 2
%! J Regul Econ
%R 10.1007/s11149-011-9158-z
%0 Journal Article
%J IEEE Transactions on Power Systems
%D 2011
%T Reserve Requirements for Wind Power Integration: A Scenario-Based Stochastic Programming Framework
%A Anthony Papavasiliou
%A Shmuel S. Oren
%A Richard P. O'Neill
%K power system reliability
%K reliability and markets
%K reserve requirements
%K RM10-001
%K uncertainty
%K wind power
%X We present a two-stage stochastic programming model for committing reserves in systems with large amounts of wind power. We describe wind power generation in terms of a representative set of appropriately weighted scenarios, and we present a dual decomposition algorithm for solving the resulting stochastic program. We test our scenario generation methodology on a model of California consisting of 122 generators, and we show that the stochastic programming unit commitment policy outperforms common reserve rules.
%B IEEE Transactions on Power Systems
%V 26
%P 2197 - 2206
%8 11/2011
%N 4
%! IEEE Trans. Power Syst.
%R 10.1109/TPWRS.2011.2121095
%0 Journal Article
%J IEEE Transactions on Power Systems
%D 2011
%T Smart Flexible Just-in-Time Transmission and Flowgate Bidding
%A Kory W. Hedman
%A Richard P. O'Neill
%A Emily Bartholome Fisher
%A Shmuel S. Oren
%K reliability and markets
%K RM08-001
%X There is currently a national push to create a smarter grid. Currently, the full control of transmission assets is not built in network optimization models. With more sophisticated modeling of transmission assets, it is possible to better utilize the current infrastructure to improve the social welfare. Co-optimizing the generation with the network topology has been shown to reduce the total dispatch cost. In this paper, we propose the concept of just-in-time transmission. This concept is predicated on the fact that transmission that is a detriment to network efficiency can be kept offline when not needed and, with the proper smart grid/advanced technology, can be switched back into service once there is a disturbance. We determine which lines to have offline based on the optimal transmission switching model previously proposed. A secondary topic of this paper focuses on flowgate bidding. Approved by the Federal Energy Regulatory Commission and implemented within the SPP and NYISO networks, flowgate bidding is defined as allowing a line's flow to exceed its rated capacity for a short period of time for a set penalty, i.e., price. We demonstrate the effectiveness of these models by testing them on large-scale ISO network models.
%B IEEE Transactions on Power Systems
%V 26
%P 93 - 102
%8 02/2011
%N 1
%! IEEE Trans. Power Syst.
%R 10.1109/TPWRS.2010.2047660
%0 Journal Article
%J IEEE Transactions on Power Systems
%D 2010
%T Co-Optimization of Generation Unit Commitment and Transmission Switching With N-1 Reliability
%A Kory W. Hedman
%A Ferris, Michael C.
%A Richard P. O'Neill
%A Emily Bartholome Fisher
%A Shmuel S. Oren
%K reliability and markets
%K RM08-001
%X Currently, there is a national push for a smarter electric grid, one that is more controllable and flexible. The full control of transmission assets are not currently built into electric network optimization models. Optimal transmission switching is a straightforward way to leverage grid controllability: to make better use of the existing system and meet growing demand with existing infrastructure. Previous papers have shown that optimizing the network topology improves the dispatch of electrical networks. Such optimal topology dispatch can be categorized as a smart grid application where there is a co-optimization of both generators and transmission topology. In this paper we present a co-optimization formulation of the generation unit commitment and transmission switching problem while ensuring N-1 reliability. We show that the optimal topology of the network can vary from hour to hour. We also show that optimizing the topology can change the optimal unit commitment schedule. This problem is large and computationally complex even for medium sized systems. We present decomposition and computational approaches to solving this problem. Results are presented for the IEEE RTS 96 test case.
%B IEEE Transactions on Power Systems
%V 25
%P 1052 - 1063
%8 05/2010
%N 2
%! IEEE Trans. Power Syst.
%R 10.1109/TPWRS.2009.2037232
%0 Journal Article
%J Energy Systems
%D 2010
%T Economic analysis of the N-1 reliable unit commitment and transmission switching problem using duality concepts
%A Richard P. O'Neill
%A Kory W. Hedman
%A Krall, Eric A.
%A Anthony Papavasiliou
%A Shmuel S. Oren
%K power system economics
%K power system reliability
%K reliability and markets
%K RM08-001
%X Currently, there is a national push for a smarter electric grid, one that is more controllable and flexible. Only limited control and flexibility of electric assets is currently built into electric network optimization models. Optimal transmission switching is a low cost way to leverage grid controllability: to make better use of the existing system and meet growing demand with existing infrastructure. Such control and flexibility can be categorized as a “smart grid application” where there is a co-optimization of both generators or loads and transmission topology. In this paper we form the dual problem and examine the multi-period N-1 reliable unit commitment and transmission switching problem with integer variables fixed to their optimal values. Results including LMPs and marginal cost distributions are presented for the IEEE RTS 96 test problem. The applications of this analysis in improving the efficiency of ISO and RTO markets are discussed.
%B Energy Systems
%V 1
%P 165 - 195
%8 5/2010
%N 2
%! Energy Syst
%R 10.1007/s12667-009-0005-6
%0 Conference Paper
%B 2009 IEEE/PES Power Systems Conference and Exposition (PSCE)2009 IEEE/PES Power Systems Conference and Exposition
%D 2009
%T Analyzing valid inequalities of the generation unit commitment problem
%A Kory W. Hedman
%A Richard P. O'Neill
%A Shmuel S. Oren
%K reliability and markets
%K RM08-001
%X The use of Mixed Integer Programming (MIP) within the electric industry is increasing. Many US ISOs are testing and planning to use MIP in the near future or they are already using MIP. There are various MIP formulations published for generation unit commitment with little consensus as to which formulation is preferred. In particular, various valid inequalities are used to model the minimum up and down time constraints for generation unit commitment. In this paper, we first discuss valid inequalities and facet defining valid inequalities. We then present and compare these previously published valid inequalities and we demonstrate why certain valid inequalities dominate other valid inequalities. We also present previously published facet defining valid inequalities.
%B 2009 IEEE/PES Power Systems Conference and Exposition (PSCE)2009 IEEE/PES Power Systems Conference and Exposition
%I IEEE
%C Seattle, WA, USA
%P 1 - 6
%8 03/2009
%@ 978-1-4244-3810-5
%R 10.1109/PSCE.2009.4840214
%0 Journal Article
%J IEEE Transactions on Power Systems
%D 2009
%T Optimal Transmission Switching With Contingency Analysis
%A Kory W. Hedman
%A Richard P. O'Neill
%A Emily Bartholome Fisher
%A Shmuel S. Oren
%K CERTS
%K power system economics
%K reliability and markets
%K RM08-001
%X In this paper, we analyze the N-1 reliable dc optimal dispatch with transmission switching. The model is a mixed integer program (MIP) with binary variables representing the state of the transmission element (line or transformer) and the model can be used for planning and/or operations. We then attempt to find solutions to this problem using the IEEE 118-bus and the RTS 96 system test cases. The IEEE 118-bus test case is analyzed at varying load levels. Using simple heuristics, we demonstrate that these networks can be operated to satisfy N-1 standards while cutting costs by incorporating transmission switching into the dispatch. In some cases, the percent savings from transmission switching was higher with an N-1 DCOPF formulation than with a DCOPF formulation.
%B IEEE Transactions on Power Systems
%V 24
%P 1577 - 1586
%8 08/2009
%N 3
%! IEEE Trans. Power Syst.
%R 10.1109/TPWRS.2009.2020530
%0 Journal Article
%J IEEE Transactions on Power Systems
%D 2008
%T Optimal Transmission Switching—Sensitivity Analysis and Extensions
%A Kory W. Hedman
%A Richard P. O'Neill
%A Emily Bartholome Fisher
%A Shmuel S. Oren
%K CERTS
%K power system economics
%K reliability and markets
%K RM08-001
%X In this paper, we continue to analyze optimal dispatch of generation and transmission topology to meet load as a mixed integer program (MIP) with binary variables representing the state of the transmission element (line or transformer). Previous research showed a 25% savings by dispatching the IEEE 118-bus test case. This paper is an extension of that work. It presents how changing the topology affects nodal prices, load payment, generation revenues, cost, and rents, congestion rents, and flowgate prices. Results indicate that changing the topology to cut costs typically results in lower load payments and higher generation rents for this network. Computational issues are also discussed.
%B IEEE Transactions on Power Systems
%V 23
%P 1469 - 1479
%8 08/2008
%N 3
%! IEEE Trans. Power Syst.
%R 10.1109/TPWRS.2008.926411