Improvement of source voltage and load current harmonic mitigation using UPQC: A survey

This paper describes a novel reference signal generation of supply voltage and load current by using series active power filter and shunt active power filter for the power quality improvement such as voltage sag/swell and harmonic current compensation generated due to nonlinear loads. The approach of fuzzy logic control in shunt active power filter is linguistic description, so it does not require a mathematical model of the system. The application of the Mamdani-type fuzzy logic controller to a three-phase shunt active power filter is investigated. The controller is capable of controlling dc capacitor voltage and generating reference source currents. Hysteresis current controller is used for current control in PWM inverter. The simulation results reveal that the active filter performs perfectly in conjunction with fuzzy logic controller. Now, this paper develops the integration principles of shunt current compensation and series voltages compensation, both based on instantaneous active and non-active powers, directly calculated from a-b-c phase voltages and line currents. Simulation results are presented to validate the proposed UPQC control strategy.