不均匀升压的七电平开关电容逆变器  

Seven-level Inverter Based on Switched Capacitor With Uneven Boost

作　　者：李小宝 冯浩田 李圣清[1,2] 颜石 LI Xiao-bao;FENG Hao-tian;LI Sheng-qing;YAN Shi(Hunan University of Technology,Zhuzhou 412007,China;不详)

机构地区：[1]湖南工业大学电气与信息工程学院,湖南株洲412007 [2]湖南省光伏智能电网控制工程研究中心,湖南株洲412007

出　　处：《电力电子技术》2023年第4期9-13,18,共6页Power Electronics

基　　金：国家自然科学基金(51977072);湖南省教育厅优秀青年项目(18B305)。

摘　　要：新能源接入电网需要更可靠的逆变器,针对现有多电平逆变器存在拓扑结构复杂和功率器件电压应力高等问题,提出一种不均匀升压的7电平开关电容逆变器。该拓扑结构由双电容开关模块和全桥电路组成,以较少的器件数量和低电压应力实现两倍增益的7电平输出。采用最近电平逼近法和基频调制策略控制开关管的导通顺序,实现电容与电压源的串并联。拓扑结构简单、开关损耗和电压纹波小,且满足电容电压自平衡和不均匀升压功能,极大地降低了电压谐波的畸变率,提高逆变器转化效率。最后对逆变器拓扑结构的工作原理、调制策略和电路参数进行了理论分析,并通过仿真和实验验证了该拓扑结构的可行性与有效性。More reliable inverters are needed when new energy access to the grid requires,aiming at the problems of complex topology and high voltage stress of power devices in existing multi-level inverters,a seven-level switched capacitor inverter with uneven boost is proposed.The topology is composed of a dual-capacitor switching module and a full-bridge circuit,to achieve a double gain seven-level output with fewer devices and low voltage stress.The nearest level approximation method and the fundamental frequency modulation strategy are used to control the conduction sequence of the switch,to realize the series-paraell connection of the capacitor and voltage source.The topology is simple,the loss and voltage ripple are small,and the capacitor voltage self-balancing and uneven boost function is satisfied.It greatly reduces the distortion rate of voltage harmonics and improves the inverter conversion efficiency.Finally,the operation principle,modulation strategy and circuit parameters of the inverter are analyzed theoretically,and the feasibility and correctness of the proposed topology are verified by simulation and experiment.

关 键 词：多电平逆变器 开关电容 低电压应力 不均匀升压 

分 类 号：TM464[电气工程—电器]