采用三次谐波注入调制策略的模块化多电平换流器稳态运行特性解析分析及优化  

Analysis and Optimization on Third Harmonic Injection Strategy for Steady-state Operation of Modular Multilevel Converter

作　　者：孙海峰[1] 黄家晨 马龙[1] SUN Haifeng;HUANG Jiachen;MA Long(School of Electrical and Electronic Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学电气与电子工程学院,河北保定071003

出　　处：《华北电力大学学报（自然科学版）》2020年第6期32-41,共10页Journal of North China Electric Power University：Natural Science Edition

基　　金：中央高校基本科研业务费面上基金项目(2019MS080).

摘　　要：采用三次谐波注入调制策略能够提高直流侧电压利用率、降低功率半导体器件所承受的电流应力、降低子模块电容电压纹波。但采用三次谐波注入策略会在桥臂电压中引入五次、七次谐波分量,导致MMC输出电压中含有大量五次、七次谐波,因此有必要对其进行分析并优化。针对采用三次谐波注入调制策略的MMC,应用开关函数,在投入环流抑制的情况下分析了注入三次谐波对子模块电容电压的影响,并对桥臂电压的基波分量、各次谐波分量进行了理论分析。在合理忽略次要因素的前提下,得到了桥臂电压五次、七次谐波分量、电容电压直流分量的理论解析式。随后根据理论解析式对三次谐波注入调制策略进行了优化,减小了桥臂电压的五次、七次谐波分量。最后,在PSCAD/EMTDC中搭建了MMC仿真模型,并进行对比,验证了所得解析式的精确度和所提优化方法的有效性。所得理论解析式准确度较高,优化策略简单、能为采用三次谐波注入调制的MMC的工程应用提供理论基础,具有较高的理论和应用价值。The third harmonic injection modulation strategy has advantages and disadvantages.It improves DC side voltage utilization,reduces current stress on the power semiconductor device,and alleviates the voltage ripple of the sub-module capacitor.However,it also introduces into the bridge arm voltage the fifth and seventh harmonic components which are therefore contained in the modular multilevel converter(MMC)output voltage.Considering that,we apply the switch function to the analysis of its influence on sub-module capacitor voltage under the circulating current suppression.Moreover,we also theoretically analyze the fundamental wave and harmonic wave components of bridge arm voltage.On the premise of ignoring the secondary factors,we obtain the theoretical analytical formulas of the fifth and seventh harmonic components of the bridge arm voltage as well as the DC component of the capacitor voltage.The formulas help optimize the strategy in terms of reducing the fifth and seventh harmonic components of the bridge arm voltage.Finally,the MMC simulation model is built in PSCAD/EMTDC.After comparison,it is verified that the obtained analytical formula is accurate and the proposed optimization method is simple and effective,which enables them to the engineering application of MMC using third harmonic injection modulation theoretically and practically.

关 键 词：模块化多电平换流器 三次谐波注入 稳态运行特性 解析式 优化 

分 类 号：TM614[电气工程—电力系统及自动化]