MMC-HVDC通用启动控制策略研究

在基于模块化多电平换流器高压直流输电系统(MMC-HVDC)正常运行之前需对换流器桥臂子模块电容充电,为了减少预充电阶段产生的电压电流冲击,需对系统的预充电启动策略进行设计。以电容电压实时排序算法为基础,分析了换流器不可控充电阶段特性。在可控阶段,根据子模块闭锁和旁路的运行状态提出了子模块的开环预充电方案,该方案适用于不同类型子模块且无需PI参数整定。最后,在Matlab/Simulink中搭建换流站预充电模型对所提策略进行验证。

Research on Universal Start up Control Strategy of MMC-HVDC

The capacitor of the inverter bridge arm sub-module needs to be charged before the normal operation of MMC-HVDC,in order to reduce the voltage and current surges in pre-charge phase and the design of the system's pre-charge startup strategy is required.Based on the real-time sequencing algorithm of capacitor voltage,the characteristics of the uncontrollable charging phase of the MMC was analyzed.In the controllable stage,an open-loop pre-charging scheme of the sub-module was proposed according to the operating state of the sub-module blocking and bypass.The scheme was applicable to different types of sub-modules and did not require PI parameter tuning.At last,the pre-charging model of converter station was built in Matlab/Simulink to verify the proposed strategy.