Designing of STATCOM controllers for transient stability improvement of two machine system

Abstract

Transmission networks of modern power systems are becoming increasingly stressed because of growing demand and restrictions on building new lines. One of the consequences of such a stressed system is the threat of losing stability following a disturbance. Flexible ac transmission system (FACTS) devices are found to be very effective in a transmission network for better utilization of its existing facilities without sacrificing the desired stability margin. Flexible AC Transmission System (FACTS) such as Static Synchronous Compensator (STATCOM) and Static VAR Compensator (SVC), employ the latest technology of power electronic switching devices in electric power transmission systems to control voltage and power flow. A static synchronous compensator (STATCOM) is a shunt device of the flexible AC transmission systems (FACTS) family . The STATCOM regulates voltage at its terminal by controlling the amount of reactive power injected into or absorbed from power system. When system voltage is low, STATCOM generates reactive power and when system voltage is high it absorbs reactive power. In this Thesis different STATCOM controllers i.e. based on Fuzzy Logic, Fuzzy-PI and ANFIS based are designed for improving transient stability of two machine systems. Proposed controllers are implemented under MATLAB/SIMULNK environment. Results of Fuzzy based and Fuzzy-PI based controllers installed with two machine system compared with conventional PI based STATCOM controller.