柔性直流电网稳定控制系统切机策略研究OA

To ensure the secure and stable operation of voltage source converter-based high voltage direct current(VSC-HVDC) grids,dedicated stability control systems must be deployed,and effective control strategies are essentialfor their implementation. The control modes of converter valves and the associated topological relationships inVSC-HVDC grids are analyzed. The transmission capacity of the DC grid and that of the sending-end single stationare defined,and corresponding calculation methods are proposed. Based on the difference between the pre-faulttransmitted power and the real-time transmission capacity,the surplus power of both the DC grid and the sendingendsingle station under fault conditions is calculated. From two perspectives—generator tripping based on pre-faultgeneration output and generator retention based on post-fault residual transmission capacity—a surplus power allocationstrategy for generator tripping among sending-end stations is proposed. The proposed method decouples the stabilitycontrol strategy from DC control modes and grid operating conditions,thereby significantly reducing engineeringimplementation complexity. The stability control system developed based on the proposed strategy has been validatedthrough real-time closed-loop digital simulation and practical grid operation,demonstrating its applicability tocomplex DC grids.