PSO based generator rescheduling for relieving transmission overload

Power system congestion has become one of the most significant problems faced by system operators (SO) around the globe after the restructuring of the electricity industry. It creates hurdle in the smooth functioning of deregulated electricity market and causes an increased cost associated with it. So the investigation of congestion management techniques is of vital interest. This paper presents a congestion management algorithm by optimally rescheduling the generator active power outputs. But all the generators in the system may not be taking part in the rescheduling process. Participating generators are optimally selected based on the generator sensitivities to power flow on congested lines. The algorithm manages congestion effectively ensuring minimum rescheduling cost of participating generators satisfying power balance, generator operating limits and line flow constraints. Algorithm is based on Particle Swarm Optimization (PSO) which minimizes the deviation between the rescheduled and scheduled generator power output levels. The usefulness of this methodology has been studied using the IEEE standard test systems. The IEEE standard test systems used are IEEE 30 bus and IEEE 57 bus.