改进的三电平逆变器变虚拟空间矢量调制策略  

Improved Variable Virtual-space-vector Modulation Strategy for Three-level Inverter

作　　者：周冠卿 张国荣[1,2] 解润生 王春鹏 陈伟伦[1,2] ZHOU Guanqing;ZHANG Guorong;XIE Runsheng;WANG Chunpeng;CHEN Weilun(School of Electrical Engineering and Automation,Hefei University of Technology,Hefei 230009,China;Research Center for Photovoltaic System Engineering of Ministry of Education(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,安徽省合肥市230009 [2]光伏系统教育部工程研究中心(合肥工业大学),安徽省合肥市230009

出　　处：《电力系统自动化》2023年第1期172-182,共11页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2017YFB0903100)。

摘　　要：中点电位平衡问题始终是中点钳位型(NPC)三电平逆变器研究的热点问题。文中首先介绍了NPC逆变器的拓扑结构,并分析了传统虚拟空间矢量调制的工作原理及不足之处。在此基础上,为提高中点电位平衡效果,提出一种改进的变虚拟空间矢量调制方法。该方法首先通过引入变虚拟中矢量平衡因子来重新定义虚拟中矢量,然后分析其在单位开关周期内所能产生的电荷量并据此确立矢量顺序,从而在保持中点电位稳态精度的基础上,提高其动态平衡速度。此外,在确立矢量顺序的过程中,分析了系统的输出状态并引入相占空比法进行优化,以减小系统在动态平衡过程中的输出状态切换次数。仿真和实验结果验证了所提调制算法的有效性。The neutral point potential balance is always a hot topic in the research of the neutral point clamped(NPC) three-level inverter. The topology of the NPC inverter is introduced and the working principle and shortcomings of the traditional virtual space vector modulation strategy are analyzed in this paper. On this basis, to improve the balance effect of neutral point potential, an improved variable virtual-space-vector modulation algorithm is proposed. The virtual medium vector is redefined by introducing the variable virtual medium vector balance factor. Then the amount of charge generated by the virtual medium vector in a unit switching cycle is analyzed and the vector order is established accordingly, to improve its dynamic balance speed on the basis of maintaining the steady-state accuracy of the neutral point potential. In addition, in the process of establishing the vector sequence,the output state of the system is analyzed and the phase duty cycle method is adopted for optimization, to reduce the output state switching times of the system in the process of dynamic balance. Finally, the effectiveness of the proposed modulation method is verified by simulation and experiments.

关 键 词：三电平逆变器 虚拟空间矢量 平衡因子 中点平衡 相占空比法 输出状态优化 

分 类 号：TM464[电气工程—电器]