应用于MMC换流阀的新型子模块电容电压波动抑制策略  

A Novel Suppression Strategy of Sub-Module Capacitor Voltage Fluctuation Applied to MMC Converter Value

作　　者：杨银国 于珍 李力 刘洋 陆秋瑜 YANG Yinguo;YU Zhen;LI Li;LIU Yang;LU Qiuyu(Power Dispatching and Control Center of Guangdong Power Grid Co.,Ltd.,Guangzhou 510030,China)

机构地区：[1]广东电网有限责任公司电力调度控制中心,广州510030

出　　处：《南方电网技术》2023年第8期58-66,共9页Southern Power System Technology

基　　金：中国南方电网有限责任公司重点项目(GDKJXM20198246)。

摘　　要：模块化多电平换流器(modular multilevel converter,MMC)的体积和建造成本主要受到子模块电容的限制。主动注入二倍频环流或者三次谐波电压是一种有效的降容方式,但已有的谐波注入策略大多采用离线查表的方式计算注入参数,当工况发生变化时,需要重新计算注入参数,不适用于工况频繁变化的场景,且对于二者同时注入的耦合效应尚缺少分析。为此,首先分析了二、三次谐波协同注入对子模块电容电压波动的影响,接着研究了其对MMC运行特性的影响并给出注入参数的约束条件。然后,基于对子模块电容电压波动的分析,给出了谐波协同注入参数的优化结果。最后,在PSCAD中搭建了双端MMC模型,对所提策略进行了仿真验证,结果表明谐波协同注入策略能够有效抑制子模块的电容电压波动。The volume and cost of a modular multilevel converter(MMC)are mainly limited by the sub-module capacitor.Active injection of double-frequency circulating current or third-order harmonic voltage is an effective method of capacitance reduction.However,most of the existing harmonic injection strategies apply offline table lookup methods to calculate injection parameters.When the working conditions change,the injection parameters need to be recalculated,which are not suitable for scenarios with frequently changing operating conditions.In addition,there is still lack of analysis on the coupling effect of coordinated injection of the two methods.Firstly,the influence of coordinated second-and third-order harmonic injections on the voltage fluctuation of the sub-module capacitor is analyzed,and then the effect on the MMC operating characteristics is studied and the constraints of the injec⁃tion parameters are given.Secondly,based on the voltage fluctuation of the sub-module capacitor,the optimization results of the coordinated harmonic injection parameters are given.Finally,the simulation model of MMC is built in PSCAD,and the proposed strategy is simulated and verified.The results show that the coordinated harmonic injection strategy can effectively suppress the capacitor voltage fluctuation of the sub-module.

关 键 词：MMC 子模块电容电压 谐波协同注入 降容 

分 类 号：TM743[电气工程—电力系统及自动化]