基于桥臂电流直接控制的模块化多电平换流器控制策略  

Control strategy of modular multilevel converter based on arm current direct control

作　　者：辛业春[1] 王威儒 李国庆[1] 王朝斌[1] 江守其 XIN Yechun;WANG Weiru;LI Guoqing;WANG Chaobin;JIANG Shouqi(School of Electrical Engineering,Northeast Electric Power University,Jilin 132012,China)

机构地区：[1]东北电力大学电气工程学院,吉林吉林132012

出　　处：《电力自动化设备》2018年第10期115-120,共6页Electric Power Automation Equipment

基　　金：国家电网公司科技发展计划项目(SGRIZLKJ-[2016]155)~~

摘　　要：提出一种基于桥臂电流直接控制的模块化多电平换流器控制策略,以实现对交流侧电流、直流侧电流以及内部环流的控制。通过理论分析,得到上、下桥臂传输功率与桥臂电流的关系;设计了上、下桥臂独立控制的内外环控制系统,分别对换流器三相桥臂电流进行dq变换,得到上、下桥臂各相电流的指令值;附加桥臂电流环流抑制器,以实现换流器有功、无功控制量闭环控制。在31电平柔性直流输电实验平台上对所提的控制策略进行验证,结果表明其具有精度较高、高效抑制换流器桥臂环流等优点。A control strategy of modular multilevel converter based on ann current direct control is proposed to control the AC current,DC current and arm circulating current. Through the theoretical analysis,the relationship between the transmission power of the upper/lower arm and the arm current is obtained. The inner-and outer-loop control system is designed to control the upper/lower arm independently. Respectively, the current of three-phase upper/lower arm is transformed into dq coordinate system, and the command values of each phase current of the up- per/lower arm are obtained. Then, the arm circulating current suppressor is used to realize active/reactive power closed-loop control of the converter. The control strategy is validated on the 3 l-level flexible HVDC power transmission physical experiment platform. The results show that the proposed control method has the advantages of high accuracy and high efficiency suppression of arm circulating current in the converter.

关 键 词：模块化多电平换流器 柔性直流输电 桥臂电流控制 环流 dq变换 

分 类 号：TM46[电气工程—电器] TM721.1