基于脉冲阶梯调制的级联型逆变器研究

脉冲阶梯调制(PSM)是将脉宽调制(PWM)与阶梯调制(SM)相结合,起初应用在高压直流电源系统中。将脉冲阶梯调制技术应用到逆变器领域,提出了基于脉冲阶梯调制的级联型逆变器。介绍了级联逆变器的基本拓扑,分析了PSM级联型逆变器的工作原理,研究了PSM的调制算法。该级联型逆变器具有电路结构简单、控制方法简便、开关损耗小、效率高等优点,适合高压大功率场合。建立了6模块的PSM级联型高压逆变器(可获得有效值为4 kV的输出电压)的Matlab仿真模型进行分析,给出仿真结果。仿真结果表明,PSM级联型高压逆变器的输出波形特性好,谐波含量和THD均很小。

Research on the Cascaded Inverter Based on Pulse Step Modulation

The Pulse Step Modulation(PSM),which is applied to high voltage DC power supply system in the beginning,is the combination of the Pulse Width Modulation(PWM) and the Step Modulation(SM).The Pulse Step Modulation is applied to inverter,and a cascaded inverter based on pulse step modulation is presented in this paper.The principle of PSM cascaded inverter is analyzed,and its computational method is studied particularly.This cascaded inverter has advantages of simple circuit structure,convenient control method,small wastage of switch,and high efficiency.It suits to the situation of high-voltage and high-power.The matlab simulation model of six modules PSM cascaded inverter(4KV virtual value of output voltage is achieved) is established and analyzed,and the results of simulation are given.The simulation results show that cascaded inverter based on pulse step modulation has good output characteristic and the harmonic and THD are very small.