Interval Type-2 Fuzzy based Performance of Dynamic Voltage Restorer for Compensation of Voltage Sag

Abstract

Dynamic Voltage Restorer is a series custom power device that is designed to offer effective solution in protecting sensitive loads from voltage disturbances. In power distribution systems about 80% of power quality problems arises due to voltage sag leading suffering of sensitive loads. Dynamic voltage restorer operates as a series voltage booster and claims to be a faultless compensating device to mitigate the voltage sag problem. In this paper the voltage at the source side suffers from voltage sag of 20% and the voltage at load side  is regulated using proportional and integral (PI) controllers. To generate reference load voltage for voltage source converter switching the synchronous reference frame algorithm is used. Enhanced values of PI controllers gains are attained using Type 2 fuzzy controllers. SRF based PI and Type2 fuzzy controllers were implemented to guarantee mitigation of sag and these were evaluated using simulation.