【摘要】 子模块故障是模块化多电平换流器(modular multilevel converter, MMC)中存在的典型问题，现有穿越策略研究中未能兼顾考虑MMC的暂态过程共模电压(common mode voltage, CMV)。针对这一问题，提出了一种无冗余MMC子模块故障下暂态CMV调制级抑制策略。首先基于首尾衔接调制控制任意时刻投入运行的上、下桥臂子模块的数量相同，实现稳态运行下的CMV抑制。然后在首尾衔接调制下进行子模块故障穿越和补偿策略设计以实现暂态CMV抑制，且无需抬高故障桥臂电容电压。从稳、暂态CMV机理出发，对所提调制与补偿方案的原理、实现过程、实现效果与改进方案进行了探讨。仿真与实验验证了所提方案的正确性与有效性。更多还原

【Abstract】 Submodule faults are typical problems in modular multilevel converter(MMC) systems. Existing ride-through strategies often fail to adequately consider the transient common mode voltage(CMV) during dynamic processes. To address this issue, a transient CMV modulation and suppression strategy for MMC submodule faults without redundancy is proposed. First, based on the head-tail connection modulation control, the number of inserted submodules in the upper and lower arms at any instant remains equal, thereby achieving CMV suppression under steady-state operation. Then, under this modulation framework, a submodule fault ride-through and compensation strategy is designed to achieve transient CMV suppression without raising the fault arm capacitor voltage. From the perspective of steady-state and transient CMV mechanisms, the principles, implementation process, performance characteristics, and possible improvements of the proposed modulation and compensation scheme are discussed. Finally, simulation and experimental results verify the correctness and effectiveness of the proposed scheme.更多还原