非对称优化脉宽组合调制H-桥级联多电平逆变器的选择性谐波控制(英文)

Study of a Synthesized Unsymmetrical Optimal PWM Technique of Selective Harmonic Controlling for Cascaded H-Bridge Multi-Level Inverters

本文提出了一种改进型非对称优化脉宽调制方法,其目的是减少求解相对于常规非对称优化控制方法的方程模型计算量。提出的优化脉冲波形由一种非对称优化波形和众所周知的选择性谐波消除法SHE的优化脉冲波形组合而成,建立了超越方程的数学模型,运用SHE方法的完全解作为经验初值,采用牛顿迭代法获得了关于开关角方程组的求解结果,特别的是,举例给出了该方法对特定5次谐波调幅调相的控制范围,并给出了对五次谐波进行调幅调相控制的三维开关角的解轨迹图。最后采用仿真试验,运用FFT分析方法验证了该方法控制级联H-桥多电平逆变器线电压输出的选择性谐波控制的有效性。

An improved unsymmetrical optimal pulse-width modulation（PWM） technique is proposed in this paper.The aim of this proposed technique is to decrease the relative calculation burden of a conventional unsymmetrical optimal PWM technique.The proposed optimal pulse pattern is synthesized by one well-known optimal pulse pattern of SHE（Selective Harmonic Elimination） technique and an unsymmetrical optimal pulse pattern.The transcendental mathematical equations are developed.Using the prior results of all complete solutions of SHE technique the solutions of the proposed equations are found by Newton iteration method.In particularly,a control range of a specific 5th harmonic is given by this proposed technique,and a three-dimensional diagram of switching angles about controlling of this harmonic according to its amplitude and phase angle is shown.Finally the modulation performance of the proposed technique for cascaded H-bridge inverters of line-voltage output is simulated and demonstrated by FFT analysis for its validity.