一种基于方波注入的星形级联静止同步补偿器的负序电流补偿策略  

Zero-Sequence-Voltage Injection Based on Square-Wave to Balance Cluster Voltages for Star-Connected Cascaded STATCOM

作　　者：陆道荣 魏缪宇 于宇 张钰铭 胡海兵[1] Lu Daorong;Wei Miaoyu;Yu Yu;Zhang Yuming;Hu Haibing(College of Automation Engineering Nanjing University of Aeronautics and Astronautics,Nanjing 211100 China;Zhejiang Huazheng Inspection&Testing Co.Ltd,Jinhua 321002 China)

机构地区：[1]南京航空航天大学自动化学院,南京211100 [2]浙江华正检测有限公司,金华321002

出　　处：《电工技术学报》2022年第6期1482-1494,共13页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(52007081)。

摘　　要：星形级联H桥静止同步补偿器(SCHB STATCOM)补偿负序电流时会产生三相不平衡有功功率,造成相间直流电压不均衡。为了实现相间直流电压均衡,通常需注入零序电压以重新分配三相有功功率。然而,传统的零序电压注入算法普遍基于有功功率的代数模型,方程组求解复杂且无法直观地表明零序电压的产生机理。此外,零序电压的注入将极大地增加STATCOM的输出电压,限制了负序电流的补偿范围。该文借助几何分析方法,构造零序电压相量在三相电流方向上的投影三角形,推导零序电压相量与该三角形外心的几何关系,揭示零序电压的产生机理,从而提出一种新的零序电压计算方法。在此基础上,进一步将零序电压以方波形式注入,提高了STATCOM的直流电压利用率,从而拓宽了负序电流补偿范围。最后,分别在SCHB STATCOM结构10kV/±1Mvar仿真和400V/±7.5kvar实验平台验证该文提出的零序电压注入算法的可行性。When star-connected cascaded H-bridge STATCOM compensates for the negative sequence current,the active power among clusters will be unbalanced,which will cause unbalanced cluster voltage.To maintain cluster voltage balance,zero sequence voltage is usually injected to redistribute the three-phase active power.However,the traditional calculation algorithms of the zero-sequence voltage are generally derived from the model based on active power,the equations are complicated and the mathematical mechanism is unclear.In addition,the injection of zero sequence voltage will greatly increase the output voltage of STATCOM,thus limiting the compensation range of the negative sequence current.This paper explores the geometric mechanism between zero sequence voltage and other electrical quantities with the help of voltage phasor diagrams,and proposes a special method for solving zero sequence voltage.To extend the range of the negative sequence current,this paper also studies a zero-sequence voltage injection method in the form of a square wave to improve the DC side voltage utilization of STATCOM.Finally,10kV/±1Mvar star CHB STATCOM simulation platform and 400V/±7.5kvar experimental testbench verify the proposed control method.

关 键 词：级联H桥STATCOM 零序电压注入 相间直流电压均衡 负序电流补偿 

分 类 号：TM461[电气工程—电器]