Implementation of iterative learning control based deadtime compensation for PWM inverters

Deadtime effects in PWM inverters are nonlinear and depend on the switching frequency of the inverters and the types of power devices, snubber circuits, and loads. Several deadtime compensation methods were proposed in the literature where some are based on the polarity of reference current. In these cases, the actual current ripples around the zero crossing cause inverter output voltage distortions. This paper discusses and implements a deadtime and current zero crossing effects compensation method based on Iterative Learning Control (ILC) technique. Preliminary off-line experimental results confirmed the feasibility of the proposed method. Note that, beside the compensation for the above effects, the proposed technique may be also used to compensate for the effects caused by snubber circuits and switching devices imperfections such as voltage drop and on/off delay.