DAMPING OF LOW FREQUENCY OSCILLATIONS IN A SINGLE MACHINE POWER SYSTEM USING UPFC BASED DAMPING AND FUZZY CONTROLLERS

Abstract

Low frequency electromechanical oscillations are inevitable characteristics of power systems and they greatly affect the transmission line transfer capability and power system stability. PSS and FACTS devices can help the damping of power system oscillations. The objective of this paper is to propose a systematic approach for damping controller design for FACTS devices. Unified Power Flow Controller (UPFC) is a well-known FACTS device that can control power flow in transmission lines. It can also replace PSS to damp low frequency oscillations effectively through direct control of voltage and power. In this paper a linear Heffron-Philips model of a Single Machine Infinite Bus system with a unified power flow controller is developed.