Analysis on Topology of DVR Used in Low-voltage Distribution Grid

Dynamic voltage restorer (DVR) is a series-connected transient voltage compensation equipment used in distribution grid aiming at dynamic power quality problems such as voltage sag and swell. The topology of DVR directly influences the output characteristics, the structure and the cost of overall DVR. This paper analyzes and compares three topologies applicable to low-voltage DVR in respect of DC voltage utilization ratio, adaptive capability to unbalance, flexibility and so on. The conclusion is reached that three-H bridge is the optimal topology for DVR used in low-voltage distribution grid.