An improved ZVS-PWM, active clamp/reset forward converter: Analysis, design and dynamic model

The soft switching converters evolved through the resonant load, resonant switch, resonant transition and active clamp converters to eliminate switching losses in power converters. An improved two switch forward converter employing active clamp/reset is proposed for DC/DC conversion applications in this paper. The proposed circuit is capable of operation at elevated switching frequencies of several hundreds of kHz, in a range of line and load variations. Steady state performance, the operating principle and theoretical analysis is outlined for the proposed forward converter and a design procedure is developed. The steady state conversion ratio and the equivalent circuit model valid for steady state and dynamic model is presented. Experimental results are presented which verifies the steady state and dynamic performance of the converter. The experimental waveforms are in agreement with the theoretical.