IMPLEMENTATION OF FUZZY LOGIC WITH UNIFIED POWER FLOW CONTROLLER FOR THERMAL POWER STATION IN INDIA

Abstract

A Unified Power Flow Controller (UPFC) is an electrical device for providing fast-acting reactive power compensation on high-voltage electricity transmission networks. The UPFC is a combination of a static synchronous compensator (STATCOM) and a static synchronous series compensator (SSSC) coupled via a common DC voltage link. UPFC is used to control the power flow in the transmission systems by controlling the impedance, voltage magnitude and phase angle. The objective in this paper is to maintain a constant voltage profile irrespective of changes in the load. This is achieved either by injecting or absorbing the reactive power. In this paper for implementing fuzzy logic approach two inputs (error voltage and capacitor value) are taken and the "Inverter Pulse" which is used for UPFC power electronic device to control the voltage is taken as an output. Case studies have been performed for National Thermal Power Station (NTPS) of a practical system in India. Simulation work in MATLab has been carried out with fuzzy controller and UPFC. It is observed that with Fuzzy and UPFC the reactive power requirement is less and a constant voltage of 420 KV has been achieved throughout the day.