Performance Analysis of FACTs Controller for Congestion Mitigation in Power System

Due to ever-increasing power demand, the power system is facing issues such as congestion, line outages, system reliability, and stability challenges. The impetus to revise the traditional power transmission theory and practice, and to introduce new concepts for improving the performance of the existing AC transmission system caused the development of flexible AC transmission system controllers (FACTs). Due to their capability of controlling transmission system parameters, the utilization of FACTs controllers has become essential to enhance the power system capability. To investigate the performance of FACTs controllers, this study incorporates the Unified Power Flow Controller (UPFC) in the power system. UPFC is used to mitigate transmission line congestion by controlling the transmission line power flow. In this paper, a modified control circuit for UPFC is implemented. Moreover, the selection of a suitable location for UPFC is necessary because of its techno-economic impacts. Therefore, this work uses a sensitivity-based approach for the selection of a suitable place of UPFC. To decide the suitable location, control parameters of UPFC along with system loss sensitivity indices are used. The model of UPFC along with the control circuit is simulated in PSCAD/EMTDC. To investigate the performance of UPFC, a five bus seven-line transmission system is used. After installing the UPFC at an appropriate location, the power flow results of transmission lines are compared with and without the usage of UPFC.