A COORDINATION MECHANISM FOR MAINTENANCE SCHEDULING OF GENERATING UNITS IN THE RESTRUCTURED POWER SYSTEMS BASED ON GAME THEORY CONSIDERING PAY-AS-BID AND MCP PAYMENT MECHANISM

This paper presents a novel approach for Maintenance Scheduling of Generating Units (MSU) in competitive electricity markets. In this environment, Generation Companies (Gencos) seek to maximize their own profits from the market and they are not no longer concern about meeting the demands and system reliability. On the other hand, Independent System Operator (ISO) is still responsible for system security and reliability. ISO tries to preserve system security with setting penalties for Gencos which maintenance scheduling of their units make system unreliable. ISO computes these penalties with calculating Expected Energy Not Supply (EENS) index and considering Value Of Lost Load (VOLL). The final profits of Gencos achieve after subtracting these penalties from their revenues. Under this situation, the MSU problem is formulated as a dynamic noncooperative game with complete information and optimal strategies of Gencos is defined with Nash Equilibrium. From other point of view, considering the two payment mechanism in different markets, i.e. Pay-as-Bid and Market Clearing Price (MCP), Gencos face with different situation for computing their profits. Numerical results for a simple two-Genco system and Roy Billinton Test System (RBTS) indicate the basic concept and applicability of proposed method. These results depict that MSU problem is very vital for Gencos in order to maximize their own profits from the market. Otherwise, without ISO supervision system reliability may not be guarantee. Also different impact of ISO’s regulation mechanism in Payas- Bid and MCP payment Mechanism is compared.