论文标题
在光负载条件下模块化多级转换器的非侵入性故障位置方法
A non-invasive fault location method for modular multilevel converters under light load conditions
论文作者
论文摘要
本文提出了一种考虑光负载条件的模块化多级转换器（MMC）的非侵入性故障位置方法。 MMC的前ART故障位置方法通常在满载条件下开发和验证。但是，据揭示，当灯负载下的开关开关上发生开关断层时，有故障的臂电流将被抑制为单极。这导致健康和故障的子模型的电容器电压随着相同的变化而增加或下降，从而增加了故障位置的难度。注入二阶循环电流的建议方法将重建MMC的双极臂电流，并扩大健康和故障SMS之间的电容器电压偏差。结果，故障位置时间大大缩短。进行模拟以验证提出的方法的有效性，表明与没有二阶循环电流注入的情况相比，断层位置时间减少到1/6。
This paper proposes a non-invasive fault location method for modular multilevel converters (MMC) considering light load conditions. The prior-art fault location methods of the MMC are often developed and verified under full load conditions. However, it is revealed that the faulty arm current will be suppressed to be unipolar when the open-circuit fault happens on the submodule switch under light load. This leads to the capacitor voltage of the healthy and faulty submodules rising or falling with the same variations, increasing the difficulty of fault location. The proposed approach of injecting the second-order circulating current will rebuild the bipolar arm current of the MMC and enlarge the capacitor voltage deviations between the healthy and faulty SMs. As a result, the fault location time is significantly shortened. The simulations are carried out to validate the effectiveness of the proposed approach, showing that the fault location time is reduced to 1/6 compared with the condition without second-order circulating current injection.
