Modeling and Control of Multi-Functional DVR Supported from Wind Energy System

Abstract

Abstract Dynamic voltage restorer (DVR) is a custom power device used for voltage compensation of sensitive loads against voltage disturbances in power distribution lines. However the DVR spend most of its time in standby mode, since voltage sags occur very infrequently, and hence their utilization is low. In principle, it would be advantageous if the series connected converter based DVR could also be used to compensate for any steady state load voltage harmonics and power flow control in the line. This paper proposes a phase angle regulator which compensates the load voltage during sag with minimum distortions and also controls the flow of power in line when there is no disturbance in the feeder, through a phase adjustment technique. The compensation process is accompanied by an exchange of power between the DVR supported from wind energy conversion system and the grid. Controller works according to progressive phase advance strategy to correct voltage sag as well as power sharing between the DVR and the network as per available power from the wind. In this paper, different control strategies of dynamic voltage restorer are analyzed with emphasis put on the compensation of voltage sag and power flow control. The proposed control performance of the multi-functional DVR is verified through the PSCAD/EMTDC simulation studies.