Optimal Generation Scheduling under Competitive Environment

This paper proposes a new solution algorithm for security constrained unit commitment (SCUC) based on Lagrangian decomposition and tabu search. In partially deregulated power system, a power company encounters such problems as power flow congestions caused by unexpected power wheeling from PPSs (Power Producer & Suppliers) and as to achieve social welfare by optimally operating own generators. These problems can be solved easily through SCUC. In this paper, tabu search application to SCUC problem is proposed. It must be noted that the concept of hypothetical generator is introduced to get a computationally feasible solution. To solve the problem, the original problem can be divided into two sub-problems through Lagrangian decomposition: the unit commitment (UC) problem of each generator for the whole time horizon and the optimal operation problem of each time zone. This paper focuses on tabu search applied to solve the UC problem combined with Lagrangian decomposition. A numerical example is shown to demonstrate the algorithm.