A review of different UPFC steady models in power flow algorithm

As the most powerful FACTS (flexible alternative current transmission systems) device, UPFC (unified power flow controller) could be considered as a multi-function controller which is capable of providing the performance of one or two FACTS device. This paper presents various UPFC steady models in load flow algorithms. Based on acquired achievement, UPFC has been researched by load injection technique, decoupled technique, n load injection technique, indirect technique, ideal transformer technique for different analysis purpose. It also discusses advantages and disadvantages of each method. In the end, based on analyzing current methods, a discussion for future is proposed.