针对基于模块化多电平换流器（modular multilevel converter，MMC）的大规模风电直流送出系统在受端交流电压跌落时出现的直流电压升高问题，提出了一种基于超级电容储能型MMC的故障穿越策略。该策略利用超级电容储能系统吸收故障期间的盈余功率，稳定直流侧电压，同时通过合理设计受端MMC的有功和无功电流分配原则，优先为受端交流电网提供无功功率支撑。故障结束后，超级电容储能系统将存储的能量释放回电网，提高了风电利用效率。还提出了超级电容储能系统的参数设计方法，包括双向Buck/Boost变换器滤波电感、超级电容的串并联数量和稳态运行时的电压参考值等。通过在PSCAD/EMTDC平台搭建仿真模型验证了所提策略能有效抑制直流侧过电压，提升系统故障穿越能力。此外，仿真结果还验证了与基于直流卸荷电路的故障穿越策略相比，所提方案在直流电压稳定情况和能量利用效率方面具有优势。

To address the issue of DC voltage rise in large-scale wind power DC transmission systems based on modular multilevel converters （MMC） during AC voltage dips at the receiving end, a fault ride-through strategy utilizing supercapacitor energy storage MMC is proposed. The strategy involves utilizing the supercapacitor energy storage system to absorb surplus power during faults, thereby stabilizing the DC bus voltage, while optimizing the active and reactive current distribution of the receiving-end MMC to prioritize reactive power support for the AC grid. After the fault, the stored energy in the supercapacitor is released back into the grid, improving the utilization efficiency of wind power. Additionally, a parameter design method is presented for the supercapacitor energy storage system, including the filter inductance of the bidirectional Buck/Boost converter, the series and parallel numbers of supercapacitors, and the voltage reference value during steady-state operation. Simulation results in PSCAD/EMTDC demonstrate that the proposed strategy effectively suppresses overvoltage on the DC side and enhances the system's fault ride-through capability. In addition, the simulation results also verify that the proposed scheme has advantages in terms of DC voltage stability and energy utilization efficiency compared with the fault ride-through strategy based on DC unloading circuit.