| 引用本文: | 韩少华,梅 军,郑建勇,吉 宇,杜晓舟.模块化多电平换流器不对称桥臂的环流稳态分析[J].电力自动化设备,2014,34(7): |
| HAN Shaohua,MEI Jun,ZHENG Jianyong,JI Yu,DU Xiaozhou.Steady-state analysis of unsymmetrical MMC bridge-arm circulating current[J].Electric Power Automation Equipment,2014,34(7): |
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| 摘要: |
| 在模块化多电平换流器（MMC）上下桥臂的电阻、电感不对称情况下，其桥臂环流的主要成分不再仅包括直流量和2次分量，因此有必要对此时的MMC桥臂环流进行定量研究。通过悬浮电容电压的变化规律，从时域角度构建描述环流特征的二阶微分方程。在稳态情况下忽略微分方程的通解，通过近似处理方法求得微分方程的特解，该特解可以有效地描述环流的稳态特性，即此时环流的主要成分为直流分量、1次分量和2次分量，还给出了此时环流的稳态表达式。通过MATLAB／Simulink平台搭建了仿真模型，仿真结果验证了理论分析的正确性和有效性。 |
| 关键词: 模块化多电平换流器 不对称 桥臂环流 二阶微分方程 稳态 换流器 |
| DOI： |
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| 基金项目:教育部博士点基金资助项目（20130092110041） |
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| Steady-state analysis of unsymmetrical MMC bridge-arm circulating current |
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HAN Shaohua, MEI Jun, ZHENG Jianyong, JI Yu, DU Xiaozhou
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School of Electrical Engineering，Southeast University，Nanjing 210096，China
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| Abstract: |
| If the resistors and inductors of the upper and lower MMC（Modular Multilevel Converter） bridge-arms are unsymmetrical，the main ingredients of its circulating current will not include only the DC component and the second harmonic component，which should be quantitatively studied. A time-domain second-order differential equation is built according to the variation rules of flying capacitor voltage. Under the steady-state condition，its general solution can be ignored and its special solution is achieved by approximation，which describes the steady-state characteristics of circulating current effectively and shows the steady-state circulating current of unsymmetrical MMC bridge-arm contains mainly the DC component，first harmonic component and second harmonic component. Its steady-state expression is also presented. The simulation model is built with MATLAB／Simulink and the simulative results verify the correctness and effectiveness of theoretical analysis. |
| Key words: MMC unsymmetry arm circulating current second-order differential equation steady-state electric converters |
