三相逆变器幅值可控的小波PWM技术

An Amplitude-controllable Wavelet PWM Technique for Three-phase Inverter

三相逆变器的小波PWM具有总谐波含量低、直流电压利用率高、易于数字化实现等优点,但其无法在三相逆变器上实现对输出电压幅值的控制,这使得小波PWM的应用受到限制。为此,在单相逆变器幅值可控的小波PWM技术基础上,在三相逆变器的小波PWM中同样引入了一个调制度变量,使它在保持原有优点的基础上增加了输出电压可调的特性。分析了三相逆变器幅值可控的小波PWM的机理,并进行了仿真和实验研究,结果证明了机理的正确性,为三相逆变器小波PWM的广泛应用提供了基础。

Wavelet PWM technique for three-phase inverter has the advantages of low total harmonic distortion （THD）, high dc voltage utilization ratio and simple digital implementation. However, it cannot control the amplitude of output voltage, which limits the application of wavelet PWM. Thus, this paper introduces a modulation ratio to wavelet PWM for three-phase inverter on the basis of amplitude-controllable wavelet PWM technique for single-phase inverter. The proposed amplitude-controllable wavelet PWM for three-phase inverter can not only maintain the advantage of the original wavelet PWM, but also adjust the amplitude of output voltage flexibly. This paper analyses the mechanism of amplitude-controllable wavelet PWM, and then carries out the simulation and experimental verification. Finally, the mechanism of the proposed method has been proved, which provides the foundation for the wide applications of waveletPWM.