The analysis and compensation of dead-time effects in three phase PWM inverters

The switching lag-time, which prevents the phase shortage of inverter arms, causes serious distortions of the output voltage of the inverter. This effect is well known as the dead-time effect. Several compensation methods have been proposed to improve the output waveforms. These proposed approaches did improve the inverter's output voltage waveforms. The improved waveforms however still suffer from the zero-crossing phenomenon. A new approach to overcome the zero current clamping in voltage-fed PWM inverters is proposed. This paper describes the analysis of dead-time effect in three-phase PWM inverters and the proposed scheme. The conventional compensation methods, as well as the zero crossing problem, are highlighted. Theoretical analysis and digital simulation were carried out to verify the analysis and the proposed scheme for dead time compensation.