Investigating the Impact of PWM Schemes on Transient Response of Power Converters: Comparative Study Between SPWM, SVPWM, and THIPWM

Abstract

Pulse width modulation (PWM) schemes are widely utilized in voltage source converters as a suitable modulator to generate controlled voltage and current signals. Moreover, several PWM schemes exist to suit different applications and converter topologies that emphasize harmonic elimination and shaping the output voltage signal. However, the transient response of PWM schemes has not been explicitly studied in the existing literature. Therefore, this paper aims to investigate the impact of three major PWM schemes on the dynamic performance of voltage-source converters (VSC), focusing on the transient response. Sinusoidal PWM (SPWM), space vector PWM (SVPWM), and third harmonic injection PWM (THIPWM) are the investigated schemes. The paper aims to evaluate the performance of two-level VSC during transient response besides the effect of the applied scheme on the decoupling between active and reactive power control loops. Furthermore, the investigations include studying the impact of the modulation index (M) on the transient response by coordinating the maximum DC link voltage and the transient AC output voltage. Different scenarios are considered to conclude the scheme's dynamic impact on VSC operation. The results reveal new findings where each scheme shows a different impact on the transient response of the converter output voltage and current signals. The impact also shows a strong relation to the modulation index that reflects the DC bus voltage impact on the AC side of the system.