Congestion management in Open Access: A Review

Since last few decades, electric supply industry is undergoing restructuring all over the world. Restructuring has brought organizational and operational changes by by the virtue of which Electricity has now become a commodity and regulated cost based electric power system is converted into price based liberalized power market. Under this competitive power market environment, number of market participants has increased and all market participants try to get benefits of cheaper sources. The tendency of getting more profit margins may cause overloading and congestion in certain transmission corridors. Thus congestion may lead to violation of voltage or transmission capacity limits and threatens the power system security and reliability. Moreover, open access in transmission system and competition in generation and distribution, has introduced a more intensified and frequently occurring problem of congestion. Also the growing congestion may lead to unanticipated divergent electricity pricing. Owing to these facts congestion management has become a crucial issue in the deregulated power system scenario. The review work to unite various publications on Congestion Management in past few decades and to present a systematic overview for providing solution methods for the same has been discussed in this paper. The cases for Congestion Management in various countries like California, Switzerland (Etrans), Japan, Australia, Thailand, UK, and Nordic Countries are studied and reviewed in this paper.