三电平NPC逆变器的一种优化CHMPWM方法

An optimal current harmonic minimum pulse-width modulation(CHMPWM) for three-level NPC inverter

研究低开关频率运行的NPC三电平逆变器同步优化PWM方法。以常规SHEPWM和常规CHMPWM的约束原理为基础,本文提出了一种开关角连续的优化CHMPWM方法。对这三种调制方法的原理和开关角计算进行了介绍,并对调制策略的谐波特性、转矩脉动进行对比分析。研究结果表明优化方法是两种常规方法的有机结合,性能得到了优化,适用于闭环矢量控制系统。

This paper introduces synchronous optimal PWM strategy of NPC three-level inverter working at low switching frequency.Based on the principle of conventional SHEPWM and conventional CHMPWM,this paper proposes an optimized CHMPWM method with continuous switching angle.The principle and the calculation process of the three modulation methods are described.The harmonic characteristic and torque ripple are compared and analyzed.The research results show that the optimized method is an organic combination of two conventional methods,and the performance is improved,which is suitable for closed-loop vector control system..