换流阀杂散电容计算及其对MMC电压应力水平的影响  

Calculation of Stray Capacitance in Converter Valve and its Influence on MMC Voltage Stress

作　　者：牛犁 贺明 熊斌宇 NIU Li;HE Ming;XIONG Binyu(State Grid Xi’an Power Supply Company,Xi’an 710032,China;School of Automation,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]国网西安供电公司,陕西西安710032 [2]武汉理工大学自动化学院,湖北武汉430070

出　　处：《智慧电力》2019年第11期104-109,共6页Smart Power

基　　金：国家自然科学基金资助项目(61703318)~~

摘　　要：换流阀为柔性直流输电系统的核心设备,由于设备结构等因素,换流阀存在杂散电容可能会影响换流阀的电压应力水平。首先建立换流阀的三维有限元电场分析模型,通过电场分析的方法得到换流阀的杂散电容;然后在其基础上建立包含换流阀杂散电容的MMC-HVDC系统宽频带模型;并分别计算MMC-HVDC系统在正常运行和故障工况下换流阀的电压应力水平;并以此指导换流阀的设计与优化。研究表明:MMC杂散电容会导致故障工况下MMC换流阀电压应力水平的增加。Converter valve is the core equipment of VSC-HVDC system.Because of the equipment structure and other factors,there is influence of stray capacitance occurred in the converter valve on its voltage stress level.To address this problem,the three-dimensional finite element analysis model of electric field in the converter valve is established firstly,obtaining the stray capacitance in the converter valve by using the electric field analysis method.Based on which,the wideband equivalent model of MMC-HVDC system with the stray capacitance in the converter valve is established.Finally,the voltage stress level of the converter valve is calculated under normal operation and fault condition respectively,providing support for the design and optimization of the converter valve.The research shows that the MMC stray capacitance will lead to an increase in the voltage stress level of the MMC converter valve under the fault conditions.

关 键 词：柔性直流输电换流阀 有限元法分析 杂散电容 宽频带模型 电压应力水平 

分 类 号：TM721[电气工程—电力系统及自动化]