Sung-Ling Chen , Ming-Tong Tsay , Hong-Jey Gow , Bidding Strategies for Electricity Suppliers in a Congestion Environment, International Journal of Electrical and Power Engineering, Volume 3,Issue 1, 2009, Pages 43-49, ISSN 1990-7958, ijepe.2009.43.49, (https://makhillpublications.co/view-article.php?doi=ijepe.2009.43.49) Abstract: This study presents a methodology, for bidding strategies of electricity participants in a congestion environment. This problem is modeled, as a 2 steps optimization problem. At the 1st step, a bidding strategy is solved to maximize its expected profit and at the second step, a curtailment strategy will be perform to maximize the participant’s profit when the system occurs the transmission congestion. An Refined Immune Algorithm (RIA) is proposed to solve the optimization problem. RIA proposes a Scale Scheme System (SSS) to improve crossover and mutation mechanism with a competition and auto-adjust scheme by using counterweight parameter. Using this SSS algorithm, RIA has advantages and some characteristics to show a better performance than many other algorithms. The IEEE 30 Bus is selected for test. Simulation results have a good result with this standard to obtain an optimal bidding strategy for electricity suppliers under the congestion environment. Keywords: Refined immune algorithm;congestion environment;IPP;bidding strategy