网压不对称H桥级联APF直流侧电压的控制  

DC voltage control strategy of cascaded H-bridge APF with unbalanced grid voltage

作　　者：黄海宏[1] 王超[1] 王海欣[1] HUANG Hai-hong;WANG Chao;WANG Hai-xin(School of Electrical Engineering and Automation,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学电气与自动化工程学院,合肥230009

出　　处：《电机与控制学报》2018年第11期37-45,共9页Electric Machines and Control

基　　金：国家自然科学基金(51177037)

摘　　要：H桥级联的拓扑结构存在直流侧电容电压不平衡的问题,特别是在网压不对称的工况下,不平衡尤为严重,影响到系统的正常运行。针对级联H桥拓扑存在的直流侧电压不平衡问题,提出一种总体、相间和相内三层电压控制策略。通过建立并分析级联H桥APF功率交换模型,找到相间、相内直流侧电压不均衡的原因。通过基波有功电流保持总体电压的稳定;通过在交流侧加入负序电压实现了三相之间功率的重新分配以实现直流侧电压的平衡;在交流侧引入一个电压矢量以实现相内电压的均衡,使得装置可以在网压不平衡工况下正常运行。最后,通过仿真和实验验证了控制方法的正确性和有效性。There is a problem of DC voltage balancing in the cascaded H-bridge topology.The unbalanced grid voltage leads to the unbalanced DC voltage which influences the steady operation of the APF system.To solve this problem,the three levels voltage control strategy which is suitable for the unbalanced grid voltage condition was proposed.A power exchange model was built to find out what makes the DC voltage between phases and among one phase unbalanced.The fundamental active current was used to keep the balance of total DC voltage.By adding a negative voltage in the AC side to redistribute the power of three phase,the DC voltage of three phase balanced is balanced.By appending a voltage vector in the AC side,voltage balancing among one phase is achieved.Finally,the simulation and experiment results prove the validity of this three level control strategy.

关 键 词：级联H桥 有源电力滤波器 不对称网压 直流电压平衡 负序电压 重复控制 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM46