TITLE:
Towards Optimal Transmission Switching in Day-Ahead Unit Commitment
AUTHORS:
Kwok W. Cheung, Jun Wu
KEYWORDS:
Transmission Switching, Market Efficiency, System Operation, Economic Dispatch
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.3 No.4,
April
14,
2015
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.