Abstract:
This paper presents dc to dc converter to eliminate the problems associated with traditional converters, they are voltage oscillation in the rectifier diodes, freewheeling period circulating losses, narrow zero voltage (ZVS) and zero current (ZCS) soft switching range. The proposed converter consists of series capacitor connected with dc to dc converter; this capacitor is used to diminish the voltage stress in the semiconductor switches, zero voltage and zero current switching can be obtained. And the asymmetric pulse width modulated (APWM) scheme is utilized in this converter to reduce the switching losses and wide soft switching can be obtained. The switching losses when turned OFF can be reduced and the energy required for commutation system also minimized by utilization of reduced voltage applied to the power switches. For load power and variable input voltage, wide soft switching range is obtained. The oscillation of the voltage output is minimized by using the auxiliary circuit on the output side of the transformer, Zero current switching for the lagging switches could be achieved and circulating losses are eliminated. In this paper gives the principle of operation, configuration of the circuit, result analysis of the proposed converter, and design example are discussed. The results are checked and validated experimentally with prototype of 500watts, 420v/12v.
