Towards Optimal Transmission Switching in Day-Ahead Unit Commitment

Kwok W. Cheung, Jun Wu

Alstom Grid, Inc., Redmond, Washington, USA.

DOI: 10.4236/jpee.2015.34015                

Abstract

Co-optimizing transmission topology with generation dispatch, and leveraging grid controllability could be a viable way to improve economic efficiency of system operations in control centers. In particular, day-ahead unit commitment is a typical business process that electric utilities deploy to ensure enough generation capacity is committed day-ahead to meet the load for the next day. In a market environment, day-ahead reliability unit commitment (DA-RUC) performs a simultaneous solution of minimizing the cost of commitment for resources to meet forecasted load, net scheduled interchange and operating reserve requirements using security constrained unit commitment (SCUC). The commitment may then be further checked by running security constrained economic dispatch (SCED) to verify that the commitment solution can be feasibly dispatched subject to system constraints and activated transmission constraints for each hour identified in the study period. This paper applies Optimal Transmission Switching (OTS) in DA-RUC using some heuristic pre-screening techniques to reduce the dimension of the OTS problem. Various pre-screening methods of candidate transmission lines for switching are proposed and compared. Simulation results will be presented to demonstrate generation dispatch combined with OTS in each hour could reduce congestion cost and significantly lower generation cost.

Keywords

Transmission Switching, Market Efficiency, System Operation, Economic Dispatch

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Cheung, K.W. (2008) Ancillary Service Market Design and Implementation in North America: From Theory to Practice. Panel Paper, Proceedings of the 3rd International Conference on Electric Utility Deregulation, Restructuring and Power Technologies (DRPT), Nanjuing, 6-9 April 2008, 66-73. http://dx.doi.org/10.1109/DRPT.2008.4523381
[2]	Wood, A.J. and Wollenberg, B.F. (1996) Power Gener-ation, Operation, and Control. 2nd Edition, John Wiley & Sons, New York.
[3]	Fisher, E.B., O’Neill, R.P. and Ferris, M.C. (2008) Optimal Transmission Switching. IEEE Transactions on Power Systems, 23, 1343-1355. http://dx.doi.org/10.1109/TPWRS.2008.922256
[4]	Chow, J.H., deMello, R. and Cheung, K.W. (2005) Electricity Market Design: An Integrated Approach to Reliability Assurance. Invited Paper, IEEE Proceeding (Special Issue on Power Technology & Policy: Forty Years after the 1965 Blackout), 93, 1956-1969.
[5]	Cheung, K.W. (2011) Economic Evaluation of Transmission Outages and Switching for Market and System Operations. Panel Paper, Proceedings of 2011 IEEE PES General Meeting.
[6]	Cheung, K.W., Wu, J. and Rios-Zalapa, R. (2010) A Practical Implementation of Optimal Transmission Switching. Proceedings of the 4th International Conference on Electric Utility Deregulation, Restructuring and Power Technologies (DRPT 2010).
[7]	Hedman, K.W., O’Neill, R.P., Fisher, E.B. and Oren, S.S. (2008) Optimal Transmission Switching—Sensitivity Analysis and Extensions. IEEE Transactions on Power Systems, 23, 1469-1479. http://dx.doi.org/10.1109/TPWRS.2008.926411
[8]	Fuller, J.D., Ramasra, R. and Cha, A. (2012) Fast Heuristics for Transmission Line Switching. IEEE Transactions on Power Systems, 27, 1377-1386. http://dx.doi.org/10.1109/TPWRS.2012.2186155
[9]	Ruiz, P.A., Foster, J.M., Rudkevich, A. and Caramanis, M.C. (2011) On Fast Transmission Topology Control Heuristics. Proceedings of 2011 IEEE PES General Meeting.
[10]	Wu, J. and Cheung, K.W. (2013) On Selection of Transmission Line Candidates for Optimal Transmission Switching in Large Power Networks. Proceedings of IEEE PES General Meeting, 21-25 July 2013, Vancouver, BC.