Research on Short-Circuit Test of 500kV Hybrid HVDC Circuit Breaker

A test was performed on the short-circuit current of a hybrid HVDC circuit breaker for the first set of flexible DC loop network system with the highest voltage class of ±500kV in the world, and this paper makes an analysis of the breaking function of a DC circuit breaker configured in a distributed manner in a symmetrical bipolar wiring mode. By setting up a four-terminal loop flexible DC power grid which has the same operation mode with that at a site and making a test program fully equivalent to a single LC oscillator supply, this paper analyzes the parameter configuration and simulation difficulties in such mode and obtains the cost and floor area required for such mode. The paper makes a detailed analysis of the equivalent strategy for the capacity reduction test and unit module test of the single LC oscillator supply and points out respective advantages and disadvantages according to the simulation result. The energy consumption process of a ZnO lightning arrester was considered comprehensively, and the transient overvoltage insulation characteristics of the whole circuit breaker was tested. According to specific case tests, the DC breaking capacity of bipolar short circuit in transient and stable states was tested, and the key factors which needs to be considered during equipment research and manufacture processes were given.