Abstract: Narrow pulse issue existing in high-frequency single-phase two-level inverters operated under high modulation ratio, Analyzed the effects of modulation ratio, carrier frequency, and dead time on narrow pulses under the strategy of Sinusoidal Pulse Width Modulation (SPWM), and obtained the distribution law of narrow pulses within the modulation wave period. Based on this, a high-quality modulation method without narrow pulses was proposed to eliminate narrow pulses within the modulation cycle of high-frequency inverters. Additionally, in order to address the waveform distortion issue at the modulation peak and valley in this method, a three-beat carrier prediction method is designed to further improve the quality of the AC output waveform through modifications to the modulation method within the narrow pulse area. Finally, a single-phase full bridge inverter experimental platform was built to verify the feasibility and effectiveness of the proposed narrow pulse-free high-quality modulation method.

Key words: narrow pulse, waveform distortion, high-frequency inverter, dead time, single phase