抑制混合级联H桥逆变器电流倒灌的调制策略  

Modulation Strategy for Suppressing Current Inrush of Hybrid Cascaded H-bridge Inverter

作　　者：李善寿[1] 黄雪婷 叶伟 颜普 肖融 LI Shanshou;HUANG Xueting;YE Wei;YAN Pu;XIAO Rong(Key Laboratory of Intelligent Building&Building Energy Saving(Anhui Jianzhu University),Hefei 230022,Anhui Province,China;Anhui Nari Jiyuan Electric Power System Tech Co.,Ltd.,Hefei 230088,Anhui Province,China)

机构地区：[1]智能建筑与建筑节能安徽省重点实验室(安徽建筑大学),安徽省合肥市230022 [2]安徽南瑞继远电网技术有限公司,安徽省合肥市230088

出　　处：《电网技术》2023年第1期387-395,共9页Power System Technology

基　　金：国家自然科学基金项目(61901006);博士科研启动项目(2020QDZ40)。

摘　　要：传统调制策略下混合级联H桥变换器会出现因高低压单元输出电压极性不一致引起的电流倒灌问题。同时多个低压单元采用不同的脉冲宽度调制(pulse width modulation,PWM)方法会导致低压单元间出现输出功率不均衡问题。针对以上问题,结合不对称三单元混合级联H桥十一电平逆变器,提出了一种基于载波层叠的改进混合载波脉宽调制方法。该方法利用载波自由度和冗余开关状态,优化了低压单元的工作方式,使高低压单元在整个输出周期内保持输出电压极性一致,解决了逆变器在传统调制方法下出现的电流倒灌问题。同时,该方法中2个低压单元均工作在高频状态,使低压单元输出电压波形正负半周互补对称,实现了低压单元间输出功率自均衡。仿真和实验结果证明了调制策略的可行性及有效性。Under the traditional modulation strategy,the hybrid cascade H-bridge converter may have the current inrush problem caused by the inconsistent output voltage polarity of the high and low voltage units.At the same time,the low-voltage units with different PWM modulation methods may cause the output power imbalance between the low-voltage units.In view of the above problems,this paper proposes an improved hybrid carrier level-shifted pulse width modulation method for the asymmetric three-unit hybrid CHB eleven-level inverter.By using the freedom of the carriers and the redundant switching states,this method optimizes the working mode of the low voltage units,maitaining the high and low voltage units the same output voltage polarities in the whole output cycle and effectively solving the current inrush problem of the inverter under the traditional modulation method.Meanwhile,working in a high frequency state,the two low voltage units ensures that the output voltage waveforms of the low voltage units are complementary and symmetrical in the positive and negative half cycles,realizing the self-balance of the output power between the low voltage units.Simulation and experiment results verify the feasibility and validity of the modulation strategy.

关 键 词：级联H桥逆变器 载波层叠调制策略 电流倒灌 功率均衡 

分 类 号：TM721[电气工程—电力系统及自动化]