考虑阀塔对地寄生参数的模块化多电平换流器子模块均压特性研究  

Research on Voltage Balancing Among MMC Sub-Modules Considering Parasitic Parameters of Valve Tower to Ground

作　　者：甄帅 范彩云 洪波 李生林 

机构地区：[1]许继电气股份有限公司,河南省许昌市461000

出　　处：《电网技术》2016年第9期2772-2779,共8页Power System Technology

基　　金：国家863高技术基金项目(2012AA050206);河南省重大科技专项(141100210100)~~

摘　　要：针对柔性直流输电工程模块化多电平换流器在软启动过程中,采用自然均压策略时出现的桥臂子模块不均压现象进行了分析。在考虑阀塔对地寄生参数的基础上,推导得出子模块电容电压存在差异的理论依据。结合子模块损耗特性,分析子模块等效输入阻抗与自然均压状态下子模块电容电压的数学关系,推导得出其数学表达式。并通过该式进一步得出自然均压状态下,子模块电容电压收敛范围及其表达式。最后搭建考虑阀塔对地寄生参数的柔性直流输电系统换流器等效仿真模型,通过仿真验证了其有效性和准确性。所得出的模块化多电平换流器在自然均压状态下,其子模块电容电压收敛范围及其表达式对实际工程设计具有一定指导意义。This paper researched uneven voltage grading among sub-modules in modular multilevel converter （MMC） soft-starting process in natural voltage grading status. Considering parasitic parameters of valve tower to ground, theoretical basis was presented, proofing voltage unbalance among sub-modules. Combining sub-modular loss feature, mathematical relationshipbetween sub-module equivalent input impedance and sub-module capacitor voltage was analyzed for natural voltage grading status. Its mathematical expression was derived. Voltage convergence range and mathematical expression of sub-modular capacitor in natural voltage grading status was obtained. Finally, system equivalent model of flexible HVDC converter system was set up considering parasitic parameters of valve tower to ground. Simulation result verified validity and accuracy of the model proposed in thispaper. Under natural voltage grading status, voltage convergence range and its mathematical expression of MMC sub-module derived from this paper has certain guiding significance for actual engineering design.

关 键 词：模块化多电平换流器 阀塔对地寄生参数 子模块均压特性 均压回路 

分 类 号：TM721[电气工程—电力系统及自动化]