基于模块化多电平变换器的静止同步补偿器桥臂不对称及其控制策略  

Asymmetric Bridge Arm of Static Synchronous Compensator Based on Modular Multilevel Converter and Its Control Strategy

作　　者：秦海鸿[1] 赵海伟[1] 马策宇 董耀文[1] 聂新[1] 

机构地区：[1]南京航空航天大学自动化学院,南京210016

出　　处：《电工技术学报》2016年第14期183-192,共10页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金面上项目(51277095);教育部博士点基金(20123218120017);南京航空航天大学青年科技创新基金(理工类)(NS2015039)资助

摘　　要：在高压大容量无功补偿领域,采用模块化多电平变换器(MMC)作为静止同步补偿器(STATCOM)主电路拓扑,目前已经在工程上得到了应用。在模块化多电平变换器上、下桥臂参数不对称时,基频交流分量在上、下桥臂之间分配不均,同时桥臂电流中的直流分量和二倍频分量也会流入交流侧。建立了桥臂参数不对称MMC-STATCOM的交流侧和直流侧模型,分析了不同频率下等效电路中桥臂不对称对稳态电流的影响,提出了抑制基频共模分量及二倍频共模分量并维持上、下桥臂直流电压稳态平衡的控制策略。仿真和实验结果验证了理论分析的正确性和控制策略的有效性。The modular multilevel converter （MMC） is a suitable topology for high-voltage high-capacity voltage source converter （VSC）. The MMC topology has been used in some static synchronous compensator （STATCOM） projects. Under asymmetric bridge-arm parameters, the fundamental-frequency AC currents distribute unequally between the upper and lower arms. Meanwhile, the DC and double-frequency components also flow into the AC side. In the paper, the equivalent models of the AC side and DC side of a three-phase MMC-STATCOM are established under asymmetric bridge-arm parameters. Based on the equivalent sub-circuits at different frequencies, the effects of asymmetric conditions on MMC-STATCOM operation are analyzed in detail. A novel control strategy is further proposed to suppress the common-current of fundamental-frequency and double-frequency while keeping the voltage balance between the upper and lower arms. Both simulation and experimental results validate the feasibility of the proposed method.

关 键 词：模块化多电平变换器 不对称 基频电流 二倍频电流 模型 

分 类 号：TM464[电气工程—电器]