Novel input DC buslines side active soft- switching cells-assisted symmetrical PWM DC-DC converters with center-rapped HF transformer link rectifier

This paper deals with a new circuit prototype of two active edge resonant cells-assisted soft-switching symmetrical PWM half-bridge inverter type DC-DC high power converter employing a high frequency planar transformer with center-tapped secondary windings and rectifier with choke-input. Its operating principle is described in detail by using switching mode transition equivalent circuits which is determined under particular switching pulse timing pattern scheme as symmetrical PWM strategy, together with its unique inherent features. The performance evaluations of its experimental PCB converter setup using IGBT power modules are actually illustrated on the basis of the power loss analysis vs. switching frequency. The practical effectiveness of new high frequency isolated DC-DC power converter treated here is particularly proved for low voltage and large current DC output implementation as high performance arc welding machines in industry. Moreover, the extended circuit topologies of DC-DC high power converter treated here and selective dual mode symmetrical PWM scheme operating at soft commutation are also demonstrated for not only large current and low voltage setting but also low current low voltage conditions.