改进的STATCOM相内直流电容电压平衡控制策略  

An Improved DC Capacitor Voltage Balance Control Strategy Among Phases for STATCOM

作　　者：史丽萍[1] 曹雪祥[1] 陈丽兵[1] 夏正龙[1] 王攀攀[1] 

机构地区：[1]中国矿业大学信息与电气工程学院,江苏省徐州市221008

出　　处：《电力系统自动化》2015年第2期119-126,共8页Automation of Electric Power Systems

基　　金：高等学校博士学科点专项科研基金资助项目(20110095110014);教育部科学技术研究重大项目(311021)~~

摘　　要：在三角形接线方式下,分析级联H桥变流器静止同步补偿器(STATCOM)直流侧电容电压稳态数学模型,重点研究电压内环对直流侧电容电压控制的影响。同时,分析不加电压内环与传统电压内环的控制策略。在此基础上,提出利用变流侧电流反馈来叠加误差信号,以实现每个H桥调制波微小的移相,省去了锁相环,算法简单易行。仿真实验证明:在STATCOM补偿无功与谐波电流时,该策略都能使各H桥直流侧电容电压达到很好的平衡,稳态误差小。最后,搭建了电压660V、容量300kvar的试验样机进行补偿特性分析,试验结果表明该策略的正确性与有效性。With a link structure of the delta-type, the steady-state mathematical model for DC side capacitor voltage is analyzed for cascaded H-bridge converters based on static synchronous compensator （STATCOM）. Special attention is paid to the influence of the voltage loop on the balanced and stable control strategy for the DC capacitor voltage. Meanwhile, strategies without a voltage inner loop and traditional voltage inner loop are researched in detail. On this basis, to achieve a slight phase shift of H-bridge modulated wave, a strategy for superposing the error signal by current feedback on the inverter side is proposed. The algorithm is simplified by forgoing the phase lock loop. Simulation results show that using the proposed control strategy, the DC capacitor voltage of H-bridges is stable and the steady-state error is reduced while STATCOM is used to compensate for reactive power and harmonic current. Finally, a cascaded STATCOM （660 V, 300 kvar） experimental prototype is developed to analyze the compensation characteristics. The correctness and effectiveness of the strategy are confirmed.

关 键 词：静止同步补偿器 级联H桥变流器 三角形接线 电容电压控制 电压内环 

分 类 号：TM761.12[电气工程—电力系统及自动化]