A Hybrid Dead- Time Elimination SVPWM Scheme for Neutral-Point-Clamped Inverters

Abstract

The switching dead-time affects the quality of the inverter output waveform, and some current conventional deadtime compensation or elimination schemes require accurate information on the current polarity, which has some limitations. This paper presents a hybrid dead-time elimination space vector pulse width modulation (HDTESVPWM) scheme for neutral-point-clamped inverters based on the three-vector space vector PWM (SVPWM) and the hybrid SVPWM. In this scheme, the SVPWM division of sectors and specific space vector combination according to the load impedance angle characteristics, will not require an accurate current polarity detection device. Simulation results demonstrate that the SVPWM control sequence generated by this scheme not only eliminates the switching dead-time that need to be set in the conventional scheme, but also significantly reduces the total harmonic distortion(THD) rate of the output current and increases the fundamental amplitude of the output voltage in the inverter.