三电平逆变器SHEPWM多组解特性比较及实验  

Comparison and Experiment of Multiple Solutions for SHEPWM Applied to Three-Level Inverter

作　　者：张永昌[1] 赵争鸣[1] 张颖超[1] 

机构地区：[1]清华大学电机系电力系统国家重点实验室,北京100084

出　　处：《电工技术学报》2007年第3期60-65,共6页Transactions of China Electrotechnical Society

摘　　要：研究了应用于三电平NPC逆变器的特定消谐(Selective Harmonic Eliminated PWM,SHEPWM)技术。传统SHE均假设波形1/4周期对称,这有助于减小方程组的维数,但同时也减少了可行解的空间,而消除低次谐波并不严格要求波形1/4周期对称。针对1/4周期对称SHE,以N=7为例给出四组解,然后进一步研究1/2周期对称下的解,从理论上证明可以存在无数组解,进一步将其分为两种不同的类型。分析和比较了1/4周期对称解和1/2周期对称解的区别和联系,以及不同类型的解在谐波特性方面的差异,并通过实验进行了验证。Selective harmonic eliminated PWM （SHEPWM） applied to three-level NPC inverter is studied in the paper. Traditional SHE assumes that the output wave is quarter symmetric, which restricts the solution space while reducing the dimension of equations. In fact, quarter-wave symmetry is not necessary to eliminate the low order harmonic. Four groups of solutions for N=7 are provided and it is proved that there exists unlimited groups of solutions for half-wave symmetry furthermore. Studies show that the solutions for half-wave symmetry can be divided into two groups, The relation and difference between quarter-wave symmetry SHE and half-wave symmetry SHE in harmonic characteristic are explored and experimentally verified.

关 键 词：三电平逆变器 特定消谐 解空间 谐波特性 

分 类 号：TM464[电气工程—电器]