Modelling and Application of Unified Power Flow Controller (UPFC)

The rapid developments on the area of power electronics have enabled the development of new equipments to be able to benefit more efficiently from the power systems. The equipments based on the power electronics have been improved under the name of Flexible Alternating Current Transmission Systems (FACTS) in the last years. Unified Power Flow Controller (UPFC) is the most widely used FACTS device to control the power flow and to optimize the system stability in the transmission line. The controller used in the control mechanism has an important effect on the performance of UPFC. According to this, the performance of UPFC for several modes of operations using different control mechanisms based on Proportional-Integral (PI) and PID based controllers has been studied. In this paper a ANFIS based controller has been developed by using ANFIS EDITOR of MATLAB using Takagi-Sugeno inference system. Then it is used in the STATCOM part of the detailed model of UPFC. The MATLAB simulation results are taken to prove the capability of UPFC on power flow control and the effectiveness of controllers on the performance of UPFC in the different operating modes. MATLAB program is used to model UPFC and to verify the performance of UPFC with different controllers.