Adaptive neuro-fuzzy damping controller design for a power system installed with UPFC

Low frequency oscillations (LFO) in power system occur usually because of lack of damping torque to overcome disturbances in power system such as changes in mechanical power. Traditionally, power system stabilizers (PSS) are being used to damp these oscillations. UPFC is a well-known FACTS device that can control power-system parameters such as terminal voltage, line impedance and phase angle. It can also replace PSS to damp low frequency oscillations effectively through direct control of voltage and power. In this paper a linearized Heffron-Philips model of a (Single Machine Infinite Bus) power system with a UPFC controller is developed. The designed Adaptive Neuro Fuzzy UPFC controller adjusts control signals by appropriately processing of the input signals, and provides an efficient damping. The results of the simulation show that the UPFC with Adaptive Neuro Fuzzy controller is more effective in damping LFO compared to UPFC with PI controller.