Family of Soft-Switched PWM Converters with Minimized Auxiliary Switch Time

In this paper, we propose a family of soft-switched pulse-width modulation (PWM) converters with main and auxiliary switches that turn on at zero current and off at zero voltage. To generalize the soft-switched PWM converters, two types of auxiliary cells are suggested. They have two saturable inductors, which are operated to reduce the reverse recovery current of the diodes and to minimize the effective on time of the auxiliary switch. The switching losses of converter switches are very low on account of soft switching. Moreover, the auxiliary switch conduction loss is minimized by reducing the auxiliary switch conduction time. By applying a boost-type converter, the converter is analyzed and its characteristics are considered. The characteristics are verified by experimental results for a 250-kHz operation for the boost-type converter. The experimental result shows that the auxiliary switch pulse width is approximately 1/20 of the main switch for the half-duty ratio of the 250-kHz operation. This result is better than the conventional one at same condition .