A unit decommitment method in power system scheduling

This paper presents a unit decommitment method for power system scheduling, Given a feasible unit commitment, our algorithm determines an optimal strategy for decommitting overcommitted units based on dynamic programming. This method is being developed as a possible post-processing tool to improve the solution quality of the existing unit commitment algorithm used at PG&E. It can also be integrated into any other unit commitment method or used as a complete unit commitment algorithm in itself. The decommitment method can also be used as a tool to measure the solution quality of unit commitment algorithms. The proposed method maintains solution feasibility at all iterations. In this paper we prove that the number of iterations required by the method to terminate is bounded by the number of units. Numerical tests indicate that this decommitment method is computationally efficient and can improve scheduling significantly. (C) 1997 Elsevier Science Ltd.