一种交直流混联双端MMC运行状态评价新方法

摘要

对于柔性直流输电技术的交直流混联系统,如何通过辨识MMC换流站各相电气信息实现对MMC换流站运行状态的评判是该研究领域的一个新问题.针对此问题,本文首先分析了交流和直流输电线路暂态扰动对MMC换流站内各桥臂电压、电流的影响.指出当交流或直流输电线路发生暂态故障时,MMC换流站内各相上下桥臂的能量分布与正常运行时存在差异.基于此现象,利用指数熵权和灰色关联分析理论,提出一种基于指数熵权-灰色关联分析法的评价方法,并将其应用到MMC换流站的运行状态评判中,实现了针对不同故障类型对换流站运行影响程度的综合评价.%For hybrid AC-DC system based on flexible HVDC technology,how to evaluate the operation state of MMC station using the phase identified electrical information of MMC is a new problem.So the influence of transient disturbance of AC/DC transmission line on the voltage and current on each bridge arm of MMC station is analyzed.It is pointed that the energy distribution of each phase bridge arm in the converter station when transient faults occur on AC/DC transmission line is different from that in normal status.Based on this phenomenon,a novel evaluation method is proposed based on exponential entropy and gray relational analysis theory,and is used to evaluate the operation state of MMC station,which realizes comprehensive assessment on the impact of different faults on the operation state of MMC station.