选择性谐波控制的通用优化多电平PWM方法

针对高电压和大功率电力电子应用系统，提出了一种涵盖双极性二阶、三阶和四阶拓扑结构的通用优化PWM方法，阐述了一种不对称多电平拓扑结构电路的工作原理。建立了以选择性谐波控制为约束条件和剩余电压谐波含量为优化目标函数的PWM数学模型，并对该优化PWM数学模型进行优化求解，获得不对称逆变器电路输出的优化电平幅度比和优化PWM调制的开关角；根据电平幅度比变量k设置多电平电路以及开关角来控制多电平电路输出，对其PWM的调制效果进行了分析。仿真试验表明，该通用多电平优化PWM方法能大幅度降低高电压和大功率电力电子应用系统的开关频率及与之相关的电磁干扰。

A General Optimal Multi Level PWM Method Based on Selective Harmonic Control

Based on the application system of high voltage and power electronics,this paper proposes a general optimal PWM method for bipolar two-level,three-level and four-level topology circuits.Firstly an unsymmetrical multi-level topology circuit and its work principle are presented.Secondly the optimal PWM mathematical model is established based on selective harmonic control as constraint conditions and the optimal goal function for residual voltage harmonic content.Then an optimization solution is made for the o...