基于源网限流贡献度配合的MMC-HVDC系统自适应故障限流策略OA北大核心CSTPCD

Fault current limiting is the key technology to ensure the safe operation of HVDC system.The existing source-side and network-side current limiting methods are usually configured independently and do not match the severity of faults,so it is difficult to balance the current limiting capability and the cost of device.To solve the above problems,this paper proposes a fault limiting strategy based on source-network coordination considering the severity of faults.Adaptive Target and failure condition oriented current limiting is realized by combining the voltage regulation of the source-side modular multilevel converter(MMC)with the fault current limiter(FCL)by means of current limiting contribution.On the premise of ensuring current limiting capability,this strategy reduces the cost of FCL configuration and the adverse impact of MMC step-down operation on the power grid.Firstly,the contribution degree of source MMC and network FCL is quantitatively analyzed respectively,and then the calculation method of source-network current limiting considering the cooperation of current limiting contribution is derived.Based on this,the adaptive fault current limiting strategy matching the fault severity is proposed.Finally,the effectiveness of the proposed strategy is verified in the electromagnetic transient simulation of PSCAD.