新型故障电流转移消耗型子模块拓扑及其故障穿越策略

The Topology and Fault Ride-through Strategy of a Novel Fault Current Transfer Consumption Sub-module

为应对模块化多电平换流器(modular multilevel converter,MMC)的直流侧短路故障,提出一种故障电流转移消耗型MMC子模块,根据不存在续流通路的特点将其称作续流通路阻断式子模块(freewheeling path blocking sub-module,FPBSM)。在对具备故障电流清除能力的MMC子模块总结分类的基础上,推演FPBSM的拓扑结构,基于二极管单向导通的特点消除续流通路,配合出口处晶闸管及控制策略,可以实现故障电流的有效清除。FPBSM在保证经济性的前提下,提高了故障电流清除的能力,确保了电容电压均衡。基于MATLAB/Simulink仿真模型及硬件实验系统,验证了FPBSM-MMC故障电流清除能力。

To deal with short-circuit faults on the DC side of modular multilevel converter(MMC),a topology of freewheeling path blocking sub-module(FPBSM)for MMC with fault current transfer function is studied.Based on the summary and classification of MMC sub-modules with the capability of clearing fault current,the topology of FPBSM is deduced.The freewheeling path is eliminated based on the unidirectional conduction characteristic of diodes,and the fault current can be eliminated by cooperating with the thyristor at the port and the control strategy.FPBSM can improve the ability of fault current clearing and ensure that the capacitor voltage is balanced on the premise of economy.Based on MATLAB/Simulink simulation model and hardware experiment system,the fault current clearing capability of FPBSM-MMC is verified.