采用电抗子模块分段投切的模块化多电平换流器降电容方法  

Capacitance Reduction Methods for Modular Multilevel Converter by Dynamically Switching Reactor Submodule

作　　者：李钰 李帅 赵成勇 许建中 曹均正 LI Yu;LI Shuai;ZHAO Chengyong;XU Jianzhong;CAO Junzheng(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University）,Beijing 102206,China;C-EPRI Electric Power Engineering Co.Ltd.,Beijing 102200,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市102206 [2]中电普瑞电力工程有限公司,北京市102200

出　　处：《电力系统自动化》2018年第19期90-97,共8页Automation of Electric Power Systems

基　　金：国家电网公司科技项目(52130A17003D)~~

摘　　要：模块化多电平换流器(MMC)子模块电容的电容电压波动使得电容值难以降低,阻碍了MMC换流阀轻型化的发展。在考虑了2次和4次相间环流的基础上,分析了子模块电容电压与桥臂电流相互影响的机理。为了降低子模块电容电压的波动水平,提出了一种以子模块形式分段投切桥臂电抗器的降容方法。分析了子模块电容电压波动的产生机理,分析了电抗子模块分段投切降容方法的原理,并设计了相应的控制策略。最后,在PSCAD/EMTDC仿真环境下搭建了双端基于MMC的高压直流(MMC-HVDC)模型,验证了所提降容策略的有效性,并与现有的环流抑制策略进行了对比分析。The fluctuation of the capacitor voltage of the modular multilevel converter（MMC）sub-module capacitor makes it difficult to reduce the capacitance value,which hinders the development of the light-weight MMC converter valve.Based on the consideration of the second and fourth inter-phase circulation,this paper analyzes the mechanism of interaction effect between that the sub-module capacitance voltage and the bridge arm current.In order to reduce the fluctuation level of the sub-module capacitor voltage,a control method for switching the bridge reactor in the form of submodule is proposed.The mechanism of capacitor voltage fluctuation of sub-module is analyzed.The principle of the reactor sub-module switching method is analyzed,and the control strategy of the method is designed.Finally,a two-terminal MMC based high-voltage direct current（MMCHVDC）model is built under the PSCAD/EMTDC simulation environment to verify the effectiveness of the strategy proposed and compared with the existing circulation suppression strategy.

关 键 词：模块化多电平换流器 子模块电容器 电压波动 降容 

分 类 号：TM46[电气工程—电器]