Active DC filter for harmonics suppression and regulating load of passive filters on the DC-side of Gezhouba Converter Station

Since being operation of +/- 500kV Gezhouba - Nanqiao (GZB - NQ) HVDC Link, China, the smoothing reactor and the capacitors of DC filters were faulted for many times for the reasons of design,construction, and the others. In order to solve it, the method of harmonics suppression and regulating of passive filters is presented using active DC filter on the DC-side of GZB Converter Station in this paper. The active de filter is connected at the bottom of one existing passive de filters at GZB converter station. The construction and control strategies of active DC filter, as well as the principle of regulating load for passive filter are presented. The digital simulation results show that the practical feasibility of control technique and regulating load scheme for passive filters proposed in this paper.