Fuzzy logic based SVC for power system transient stability enhancement

This paper presents an application of fuzzy control to determine the control signal of static VAr compensator (SVC) for improvement of power system stability. This compensation scheme relevant to flexible AC transmission systems (FACTS) technology is used worldwide to improve system dynamic performance. The device increases power transfer and improves the damping of electromechanical oscillations when used in transmission systems. The proposed controller for the SVC is based on fuzzy set theory and is called fuzzy logic controller (FLC). Input signals for the FLC are chosen as generator speed deviation and accelerated power. The quantity of reactive power supplied/absorbed by SVC is determined based on the two input signals at each sampling time. The control signal is calculated using fuzzy membership functions. The effectiveness and feasibility of the proposed control method is demonstrated by a one machine infinite bus system.