新型混合级联多电平逆变器拓扑及调制策略  

Topology and modulation strategy of novel hybrid cascaded multi-level inverter

作　　者：叶远茂 华特科 YE Yuanmao;HUA Teke(School of Automation,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学自动化学院,广东广州510006

出　　处：《电力自动化设备》2023年第2期90-95,共6页Electric Power Automation Equipment

基　　金：国家自然科学基金资助项目(51907033)。

摘　　要：为解决现有非对称级联多电平逆变器存在低压单元电流倒灌和输出电平数少的问题,提出一种基于开关电容电路的混合级联多电平逆变器。首先,在两单元非对称级联H桥型逆变器的低压单元中嵌入一个开关电容电路,有效避免了低压单元电流倒灌,且输出电平数得以增加。然后,为减少所提方案应用于三相系统时所需直流电源的数量,提出了用三电平中点箝位型或T型逆变器电路作为高压单元的三相混合级联多电平逆变器拓扑。之后,针对所提逆变器拓扑的特性,提出了含有移相载波和层叠载波的混合调制策略,在满足逆变器输出高质量正弦脉宽调制电压波形的同时,有效减小了开关电容电压纹波和开关器件的切换频率及开关应力。最后,通过实验验证了所提混合级联多电平逆变器拓扑及调制策略的可行性。In order to solve the problems of current backflow in low-voltage unit and less output levels of the existing asymmetric cascaded multi-level inverter,a hybrid cascaded multi-level inverter based on switched-capacitor circuit is proposed. Firstly,a switched-capacitor circuit is embedded in the low-voltage unit of a two-unit asymmetric cascaded H-bridge type inverter,which effectively avoids the current backflow and increases the number of output levels. Then,in order to reduce the number of DC sources required when the proposed scheme is applied to three-phase system,a three-phase hybrid cascaded multi-level inverter topology is developed by using a three-level neutral point-clamped type or T-type inverter circuit as the high-voltage unit. Afterwards,in view of the proposed inverter topology characteristics,a hybrid modulation strategy containing phase-shifted carriers and level-shifted carriers is proposed. It effectively reduces the voltage ripple of the switched-capacitors and the switching frequency of switching devices as well as the switching stress while satisfying the inverter output of high-quality voltage waveforms of sinusoidal pulse width modulation. Finally,experiments verify the feasibility of the proposed cascaded multi-level inverter topology and the modulation strategy.

关 键 词：级联多电平逆变器 开关电容 混合调制 移相载波 电流倒灌 

分 类 号：TM464[电气工程—电器]