Compensation of voltage sag and voltage interruption using DVR-PV based on fuzzy-adaptive controller

Dynamic voltage restorer (DVR) can preserve a sensitive load against electrical distribution system interruption. After connecting DVR to the system, voltage sag is quickly resolved and no voltage oscillation caused by malfunction of sensitive loads occur. When there is a high voltage sag in distribution or transmission, in order to compensate voltage to the value before fault, both reactive compensation and active power compensation should be performed which requires a DC source in DC link of power quality compensators; if there is only one capacitor in DC link, only reactive power compensation can be performed, as a result significant voltage drops cannot be modified. Distributed generation sources like photovoltaic (PV) can be used as a battery instead of DC link supply of D-FACTS devices due to DC nature of their output voltage. Performance of DVR in modifying power quality indices depends on performance of its control system. In this paper, a fuzzy adaptive controller is used instead of the conventional PI controller in the control system of the DVR-PV hybrid compensator to improve its performance in compensating voltage interruption and different types of voltage sag. DVR based on fuzzy controller performs better than DVR based on other controllers like PI. Simulation of electrical distribution system is done in the presence of DVR based on fuzzy-adaptive control scheme and PV using Matlab/Simulink.