新能源电力系统国家重点实验室(华北电力大学), 北京市 102206
State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(North China Electric Power University), Beijing 102206, China
As an effective means for renewable energy integration, the flexible DC grids requires reliable breaking of DC fault current. The time-sequence coordination of fault protection among various fault current limiting devices in the DC grid needs to be studied. In this paper, based on the pole-to-pole short circuit faults in DC grid, the time-sequence of fault protection of multi-type fault current limiting devices such as fault current limiters, DC circuit breakers(DCCB), DC/DC converters and hybrid modular multi-level converters composed of half-bridge and full-bridge sub-modules are studied. Current limiting devices are configured for different areas of the compound multi-terminal DC grid system including the meshed network and radial structure. In the meanwhile, the detection method of the change rate of fault currents is used to determine whether the DCCB is operating reliably. According to different fault areas, the time-sequence coordination plan between fault current limiting devices is proposed, and some current limiting devices are considered such as the action logic of other devices when DCCBs refuse to operate. The PSCAD/EMTDC simulation results verify the reliability and validity of the time-sequence logics of multi-type current limiting devices protection in the DC grid.
ZHU Sicheng, ZHAO Chengyong,XU Jianzhong.Time-sequence Coordination of Protection in DC Grid with Multi-type Fault Current Limiting Devices[J].Automation of Electric Power Systems,2019,43(21):195-202. DOI:10.7500/AEPS20180826003.