Analysis and accurate compensation of dead-time for three-phase DC/AC inverter

A novel approach to compensate the dead-time effect based on the existing no-dead-time technique was presented. The reason of the inverter output voltage distortion was analyzed with the consideration of the dead-time and the non-ideal characteristics of the switching devices. The proposed method was implemented by adjusting the pulse width of the original driving signals to compensate the switching delay and voltage drop effect of the power devices, thus the effects were prevented from propagating into the ac-side. An improved current polarity detecting circuit with high precision was introduced to overcome the difficulties in current polarity detecting around the zero current crossing point. A more accurate output voltage synthesis was obtained with simple logic and flexible implementation, by applying this compensation strategy to a general purpose inverter system. Experimental results verify the effectiveness of the proposed method.