Coordination of Dual-functional Dynamic Voltage Restorer and Recloser in Power Distribution System

In this paper, the coordination of a dual-functional dynamic voltage restorer (DFDVR) with recloser in power distribution system is proposed. Compared to the conventional dynamic voltage restorer (DVR), the DFDVR can not only compensate the grid voltage distortion to protect the sensitive loads but also limit the fault current to a safety value. The dual-functionality of the DFDVR is achieved by controlling antiparallel-thyristors branch, which is connected between the terminal of power converter leg and the output filter. In order to realize engineering application in the realistic power distribution system, the detail design of the key components (LC filter, transformer) is studied; then the coordination sequence diagram of the DFDVR system and the operation of recloser, during instantaneous and permanent fault, is proposed, respectively. The simulation results carried out in PSCAD/EMTDC clearly validate the correctness and feasibility of the proposed coordination operation of the DFDVR and recloser.