模块化混合式高压直流断路器研究与应用

The multi-terminal high voltage direct current (HVDC) and DC grid provide an efficient solution for improving the integration and consumption of large-scale renewable energy. The DC circuit breaker (DCB) is the core equipment for DC grid construction which can achieve fast isolation of DC faults in grid. Hybrid DCB takes advantage of both traditional mechanical and solid-state breakers, the low-loss and fast-breaking characteristics are suitable for high-voltage and large-capacity DC transmission system. The paper proposed a modular hybrid DCB topology, the operation principles as well as technical features were elaborated in detail. The mathematical analysis of DCB parameter design was given. Combined with the application requirements of Zhoushan five-terminal DC and Zhangbei DC grid, 200kV and 500kV DCB was developed, then the DCB component and prototype test were carried out. The PSCAD simulation model was established to analyze the performance of DCB in Zhoushan project, and 200kV DCB was put into operation which successfully interrupting the system short-circuit fault current and the short-circuit test current. The test and operation results verify the design correctness and prototype performance. The technology presented in the paper provides strong support for flexible and reliable multi-terminal DC and DC grid construction.