正弦脉宽调制波通用谐波计算与分析方法

针对采样型正弦脉宽调制(SPWM)技术中几种传统实现方法各有优缺点的问题,特别是在谐波含量这一重要指标上的比较,提出了一种谐波通用计算与分析方法,可作为SPWM新技术研究的辅助工具。基于MATLAB数值计算和傅里叶级数,以不对称规则采样法SPWM波的生成及其谐波计算为例,详细分析了脉宽调制(PWM)波的各次谐波和总谐波系数(THD)的计算过程。通过该方法计算对称规则采样法与不对称规则采样法SPWM波的THD值,比较结果验证了该方法的可行性。同时通过以占空比为30%的方波的谐波计算,证明了该方法的通用性。

General Harmonic Calculation and Analysis Method for Sinusoidal Pulse Width Modulation

Several traditional methods of sampling sinusoidal pulse width modulation(SPWM)technology have merits and demerits,especially in comparison with the important index of harmonic content.A general calculation and analysis method for harmonics was proposed in this paper,which can be used as an auxiliary tool for SPWM new technology research.Based on MATLAB numerical calculation and Fourier series,taking the generation of SPWM wave and its harmonic calculation by asymmetric regular sampling method as examples,the calculation processes of each harmonic and total harmonic coefficient(THD)of pulse width modulation(PWM)were analyzed in detail.The THD values of SPWM waves of symmetrical regular sampling method and asymmetrical regular samping method were calculated by this method.The comparison result verified the feasibility of the method.At the same time,the generality of the method was proved by calculating the harmonic of the square wave with duty ratio of 30%.