Security Constrained Bidding Strategy of GENCOs Based on Risk Analysis in Restructured Electricity Market

In this paper¡ Generation Companies (GENCOs) bidding in wholesale electricity market is explained with considering the effect of transmission network and uncertainty about bidding strategy adopted by rival GENCOs. Due to oligopolistic restructured electricity market¡ economic model of supply function equilibrium is used for modeling GENCOs competing. In this competition¡ each GENCO is in search of maximum profit while generation scheduling and price which paid to each GENCO is determined by Independent System Operator (ISO). Thus¡ the problem of determining optimal bidding strategy for desired GENCO is modeling by bi-level programming method. So that¡ in upper level the profit of each GENCO has been maximized and in lower level ISO with the aim of minimizing the amount of electrical energy consumers’ payment subject to secured operation of power system¡ will be clear the market. In addition¡ since each GENCO is faced with uncertainty about the strategies of rival GENCOs¡ in this paper the mentioned bi-level programming is treated as a stochastic programming and to simulate uncertainty the Monte Carlo method is used. GENCOs competition in the presence of uncertainty has been studied in the context of incomplete information game. Also by measurement of value at Risk (VaR)¡ according risk level of each GENCO bidding strategy has been adopted. The proposed methodology in this paper is implemented on a 30-bus IEEE test system¡ and the results showed a significant effect of risk level on bidding strategy adopted by each GENCO.