Time domain comparison of pulse-width modulation schemes

Abstract

This paper shows that classical space vector modulation (SVM) is functionally identical to double-sided uniform-sampled pulse width modulation (UPWM). Consequently, direct conclusions about harmonic distortion, losses, DC bus utilization, and ease of implementation are made that clarify some existing misconceptions about SVM. Since UPWM is conceptually simple and involves few steps, it is possible that computation may be reduced in practice. UPWM algorithms can avoid the sector and switch sequence tracking tasks in an SVM algorithm. The linear modulation range extension "inherent" to SVM is associated with triplen harmonic injection, and does not provide advantages over conventional third-harmonic injection techniques. The equivalence of SVM and UPWM means that SVM has spectral distortion in baseband as is known to occur in UPWM. This has implications for naturally-sampled sine-triangle PWM (NPWM)-which is known not to generate baseband distortion.