双低压型混合级联逆变器的改进混合调制  

Improved Hybrid Modulation for Hybrid Cascaded Inverter with Dual Low-voltage Cells

作　　者：胡文华 刘剑锋 HU Wenhua;LIU Jianfeng(School of Electrical and Automation Engineering,East China Jiaotong University,Nanchang 330013,China)

机构地区：[1]华东交通大学电气与自动化工程学院,南昌330013

出　　处：《电力系统及其自动化学报》2020年第2期7-13,共7页Proceedings of the CSU-EPSA

基　　金：国家自然科学基金资助项目(51567009);江西省教育厅资助一般项目(GJJ160492)。

摘　　要：为解决混合级联九电平逆变器中的电流倒灌问题和降低功率平衡方法的数字设计难度,提出了一种改进的混合调制策略。该混合调制策略可分为两步:首先,通过改进混合级联九电平逆变器拓扑及混合调制方法消除电流倒灌问题;然后再利用逻辑运算对低压单元开关管的初始驱动信号进行功率平衡优化,得到低压单元开关管的实际驱动信号,进而简化功率平衡方法。仿真和实验结果表明:该策略能够在较低调制度下,实现逆变器的高压单元工作在基波频率和2个低压单元的功率平衡。To solve the problem of reverse current in a hybrid cascaded 9-level inverter and reduce the difficulty in the digital design of the power balance method,an improved hybrid modulation strategy is proposed in this paper.The pro?posed strategy can be divided into two steps.Firstly,the problem of reverse current is eliminated by improving the hy?brid cascaded 9-level inverter topology and the corresponding hybrid modulation method.Secondly,the actual driving signals of low-voltage cell switches are obtained by using logic operation to optimize the power balance of the initial driv?ing signals of low-voltage cell switches,thus simplifying the power balance method.Simulation and experimental results show that this strategy can enable the high-voltage cells of the inverter to operate at fundamental frequency and strike a balance between the powers of two low-voltage cells at a lower modulation degree.

关 键 词：多电平逆变器 混合级联 混合调制 逻辑运算 电流倒灌 功率平衡 

分 类 号：TM46[电气工程—电器]