Z-源逆变器PWM调制策略的分析与比较

摘要

Z-源逆变器是一种具有升/降压功能的单级逆变器,较之应用广泛的电压源逆变器和级联Boost斩波电路的电压源逆变器,具有结构简单、整机效率高和系统安全可靠等优点.本文在简单介绍Z-源逆变器工作原理的基础上,重点分析了Z-源逆变器的PWM调制策略.阐述了目前为止应用于Z-源逆变器升压调制中的几种调制策略,包括简单升压调制、最大升压调制、最大恒定升压调制、三次谐波注入升压调制、直通分段SVPWM和正弦载波PWM等调制策略的实现方法,通过定性分析和定量比较,对比了各调制策略的性能,分别从升压能力、功率器件电压应力和电感电流纹波等方面讨论了他们各自的优缺点,并列出了各调制策略下Z-源逆变器的主要性能参数比对表,为Z-源逆变器的系统选型和实际应用提供理论依据.%Z-source inverter is a single-stage inverter,which has buck/boost characteristic.Compared with the widely used voltage source inverter and the voltage source inverter with cascaded boost chopper circuit,Z-source inverter has the advantages of simple structure,high efficiency and system reliability.This paper introduces the operating principle of Z-source inverter briefly,and focuses on PWM modulation strategies for Z-source inverter.Several PWM modulation strategies are presented including simple boost,maximum boost,maximum constant boost,boost modulation with third harmonic injection,short-through subsection based on SVPWM and sine carrier PWM.Through the qualitative analysis and quantity comparison,the paper contrasts the performance of different modulation strategies,sums up their advantages and disadvantages separately from boost capability,voltage stress and current ripple,and lists the parameters comparison table.All these provide a theoretical basis for system selection and application.