Medium-voltage dc (MVdc) distribution system is considered as the promising power architecture of future shipboard power system. Fault-tolerance ability is of great importance for power system on ships. In this paper, zonal dc-dc conversion system based on modular multilevel converter (MMC) and three-phase bridge rectifier are proposed with its hierarchical fault-tolerant scheme. The topology configurations of the front-end MMC with multiwinding medium frequency transformer under normal and postfault circumstances are presented. The reconfiguration scheme and fault-tolerant control strategy are also proposed to ride-through submodule (SM) level fault, phase level fault and bus level fault. Based on the hierarchical fault-tolerant scheme, redundant configuration of the MMC SM is further analyzed with the hierarchical reliability modeling. The effectiveness of the proposed control strategy is verified by the experimental results.

中文翻译：

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船用中压直流系统模块化多电平变流器面向容错的分级控制与配置


中压直流（MVdc）配电系统被认为是未来船用电力系统有前途的电源架构。容错能力对于船舶电力系统至关重要。本文提出了基于模块化多电平变换器（MMC）和三相桥式整流器的分区式DC-DC变换系统及其分级容错方案。给出了多绕组中频变压器前端MMC在正常和故障后情况下的拓扑结构。还针对穿越子模块（SM）级故障、相级故障和总线级故障提出了重构方案和容错控制策略。基于分层容错方案，通过分层可靠性建模进一步分析了MMC SM的冗余配置。实验结果验证了所提出控制策略的有效性。