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

Dynamic voltage restorer (DVR) is a series-connecte d transient voltage compensation equipment used in distribution grid aiming at dynamic power quality p roblems 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, ad aptive capability to unbalance, flexibility and so on. The conclusion is reached that three-H bridge is the o ptimal topology for DVR used in low-voltage distribution grid.