Investigation of dynamic behavior of power system installed with STATCOM

A static synchronous compensator (STATCOM) is one of the new generation flexible AC transmission system (FACTS) devices with a promising feature of applications in power system. STATCOMs are used to stabilize the system by exchanging reactive power with the power system. In this thesis, dynamic behavior of the single machine infinite bus power system with STATCOM has been investigated. Both an approximate and a detailed mathematical model are used for damping control of a power system. The effect of PID controllers in damping enhancement has been investigated. It was observed that proportional and derivative control is superior to other combinations of PID. The simultaneous control of electromechanical transient damping and STATCOM voltage variation was found to be difficult. A robust STATCOM controller design is presented. Method of multiplicative uncertainty has been employed to model the variations of the operating points in the system. The design is carried out applying robustness criteria for stability and performance. A loop-shaping technique has been employed to select a suitable open-loop transfer function, from which the robust controller is constructed. The proposed controller has been tested through a number of disturbances including three-phase faults. The robust controller designed has been demonstrated to provide extremely good damping characteristics over a good range of operating conditions.