Improved Performance of Unified Power Quality Conditioner Involving Various Power Quality Issues using Soft Computing

This paper proposes elevated performances of control technique in UPQC, Which increases the toughness against parametric perturbation of supply voltage and load and increases the tracking performances of compensating reference signal. In this paper three phase four wires Unified Power Quality Conditioner (UPQC) with four leg shunt Active Power Filter (APF) is used to compensate load voltage and supply current against distortions. A Synchronous Reference Frame theory (SRF) is used for generation of reference signal for both shunt and series converters. To improve the performances of UPQC, a fuzzy logic controller, a principal component of soft computing is used to regulate the capacitor voltage. To achieve symbolic mitigation with excellent accuracy and very quick response fuzzy adaptive hysteresis controller is designed for PWM signal generation for both series and shunt converters of UPQC. To validate the proposed controllers, different power quality issues like distorted utility voltage, voltage sag/swell, current harmonics, neutral current compensation, transient load and unbalanced load conditions are considered. From the simulation results it is proved that the proposed controllers give better compensation and fast response than conventional controllers.