采用三次谐波注入策略的模块化多电平换流器动态相量模型  

Dynamic Phasor Model of Modular Multilevel Converter With Third Harmonic Injection Scheme

作　　者：李探 梅念 陈东 乐波 马为民 李高望 LI Tan;MEI Nian;CHEN Dong;YUE Bo;MA Weimin;LI Gaowang(State Grid Economic and Technological Research Institute Co.Ltd.,Changping District,Beijing 102209,China)

机构地区：[1]国网经济技术研究院有限公司

出　　处：《电网技术》2019年第9期3384-3392,共9页Power System Technology

基　　金：国家电网有限公司科技项目(52010118000B)~~

摘　　要：采用三次谐波注入策略可有效提高模块化多电平换流器(modular multilevel converter,MMC)的直流电压利用率,从而减小换流器的稳态和暂态电流应力,降低换流器的损耗,提高换流器的安全裕度和故障穿越能力。针对采用三次谐波注入策略的MMC,分析了子模块电容电压、桥臂电流、桥臂电压的主要谐波分量;通过将各次主要谐波分量表示为相量,最终建立了16阶MMC动态相量模型,然后将其线性化建立了小信号分析模型。所建模型可方便地与直流侧、交流侧以及控制系统进行接口,适用于采用三次谐波注入策略的MMC稳态解析分析和小信号稳定性分析。通过在PSCAD下建立电磁暂态仿真模型并对比仿真结果和解析计算结果,验证了所建立模型的精确性。Third harmonic injection scheme can effectively increase dc voltage utilization ratio of modular multilevel converter,thus decreasing steady-state and transient-state current stress,reducing the loss,and increasing safety margin and fault ride-through ability.In this paper,based on the MMC with third harmonic injection scheme,the harmonics of sub-module capacitor voltage,arm current,arm voltage are analyzed.Then all the harmonics are expressed with phasors,and a 16-order dynamic phasor model is established.Also a small-signal model is established by linearizing the dynamic phasor model.The established model provides convenient interface with dc side,ac side and control system,and can be applied to steady-state analytical analysis and small-signal stability analysis.Finally,an electromagnetic model based on PSCAD is established.Simulation results are compared with the analytical results,thus validating accuracy of the established model.

关 键 词：三次谐波注入 模块化多电平换流器 柔性直流输电 动态相量模型 

分 类 号：TM721[电气工程—电力系统及自动化]