Analysis and Experiment of a Micro-Loss Multi-Port Hybrid DCCB for MVDC Distribution System

Medium voltage direct current (MVdc) distribution system has numerous advantages over medium voltage alternative current distribution system. However, two shortcomings of the existing hybrid direct current circuit breaker (DCCB) with load current switch, including high construction cost and high operating losses, have constrained the application of existing hybrid DCCBs in MVdc distribution system. To overcome these two shortcomings, a novel multi-port hybrid DCCB with negative voltage source (NVS) has been proposed in this paper. First, the general topology and working principle of the multi-port hybrid DCCB with NVS are presented. Then, focused on the current commutation method and economic performance, comparisons between different hybrid DCCBs have been carried out. The analysis shows that by using multi-port hybrid DCCB with NVS, the construction cost could be reduced dramatically and the operating losses could be reduced to be comparable with alternative current circuit breaker, which are negligible. In the end, to fill the blank of experimental research, based on the topology of multi-port hybrid DCCB with NVS, a prototype with rating voltage of 2 kV has been established, and the test result have verified the multi-port hybrid DCCB with NVS.