A Hybrid LR-EP for Solving New Profit-Based UC Problem under Competitive Environment

With the opening of the power industry to competition, power system structure is changing. According to these changes, power system operation, planning and control need modifications. In the past, utilities had to produce power to satisfy their customers with objective to minimize costs and all demand/reserve were met. However, it is not necessary in a restructured system. Under new structure, generation companies (GenCo) schedule their generators with objective to maximize their own profit without regard for system social benefit. Power and reserve prices become important factors in decision process. This paper proposes a new tool, profit-based unit commitment (UC) considering both power and reserve generatings. The proposed method helps GenCo to make a decision, how much power and reserve should be sold in market and how to schedule generators in order to receive the maximum profit. A hybrid method between Lagrange relaxation (LR) and evolutionary programming (EP) is used for solving this problem. Simulations are carried out to show the performance of the proposed methodology.