一种新的多电平逆变器特定谐波消除脉宽调制方法

基于多电平逆变器特定谐波消除脉宽调制(SHEPWM)方法的波形对称方案，提出了一种新的多电平逆变器半周期对称波形SHEPWM方法，可以求取许多现有方法不能求得的数值解，具有通用性强、形式简单、波形灵活、易于编程、解的空间大等优点.以五电平逆变器为例，取半个周期内20个开关切换点，对调制比为0.8时的非线性方程组进行求解，求取了12组数值解，抽取其中2组进行仿真和实验研究，证明了所提SHEPWM方法的有效性和实用性.

A Novel Selective Harmonics Elimination PWM Method for Multilevel Voltage Inverters

The schemes of waveform symmetry of selective harmonic elimination (SHE) PWM methods for multilevel voltage inverters were investigated. In order to provide more opportunities for optimization design in practice, a novel generalized half wave symmetry SHEPWM method was proposed. The advantages of the proposed method include simplicity in format, flexibility in PWM waveforms and a broad solution space. Taking a five level inverter with 20 points in half a cycle as an example, twelve groups of solutions at modulation index (M) of 0.8 were obtained. Simulations based on two groups of selected keys were carried out. An experimental prototype with a five level cascade voltage inverter topology was built and investigated based on the same keys. The experimental results agree well with the simulated ones and prove the validity and practicability of the new method.