基于限流电抗器的统一潮流控制器故障渡越策略及其与保护的配合

Fault ride through strategy of unified power flow controller based on current limiting reactor and its coordination with protection

详细分析了基于模块化多电平换流器(MMC)的统一潮流控制器(UPFC)接入线路发生故障时的UPFC本体响应特性,提出一种基于限流电抗器的UPFC故障渡越策略。通过限制经过直流母线的故障电流,可使得UPFC外部故障期间并联侧MMC不闭锁,从而实现故障渡越。在此基础上,研究并提出了UPFC故障渡越策略与线路距离保护的协调配合方案,可有效解决UPFC接入后对线路距离保护的不利影响。通过PSCAD/EMTDC进行了大量仿真试验,验证了所提策略和方案的有效性。

The response characteristics of UPFC(Unified Power Flow Controller) based on MMC(Modular Multilevel Converter) in case of failure of UPFC access line are analyzed in detail,and an FRT(Fault Ride Through) strategy based on CLR(Current Limiting Reactor) is proposed,which can make MMC at the shunt side being unblocked during external fault of UPFC by limiting the fault current passing through the DC link bus. On this basis,a coordination scheme of the FRT strategy of UPFC with the line distance protection is provided,which can effectively eliminate the adverse effects on the line distance protection.Simulation experiments are carried out in PSCAD/EMTDC,and the results verify the effectiveness of the proposed FRT strategy and coordination scheme.