Congestion Management of Electricity Markets Using FACTS Controllers

Within the deregulated electricity markets of today a major issue for the Independent System Operator (ISO) is to deal effectively with congestion management. This paper provides an investigation into the benefit of the Unified Power Flow Controller (UPFC) as a viable solution to the problem of congestion management. Many deregulated electricity markets now operate in a bilateral manner, and carry out as many transactions per hour as was previously performed in a single day. The bilateral market environment is reflected in this investigation. A mathematical model of the UPFC has been incorporated into a general two-step optimization methodology for finding the optimal rating of the UPFC located at congested transmission lines. Numerical examples are presented based on the IEEE 30-bus system, and the results demonstrate the method used to find the optimum rating of the UPFC and the reduction in congestion costs the UPFC brings to a heavily congested system.