A novel dead time compensation method

Dead time that is utilized to prevent the phase shortage of inverter bridges causes serious output waveform distortion in PWM VSI and the consequent torque ripple on motor shaft. In this paper, the effect of dead time is investigated. A low cost current direction detecting circuit with high precision is presented. Based on that, a novel compensation method to suppress this output distortion is proposed. Finally the effectiveness of the method is verified by experiments together with other two types of marketing product of inverter in comparison.