Comparative considerations of soft switching PWM three-level HB dc-dc converters with high frequency link

This paper discusses the circuit topologies for simple three-level phase shift ZVS-PWM DC-DC converters in addition to the proposed three-level diode clamped and flying capacitor hybrid phase shift soft switched PWM high frequency link DC-DC converters for industrial gas metal arc welding machines. The arc welding machines for TIG, MIG and MAG require low voltage and large current DC output for high frequency linked DC-DC converters. These three-level type soft switched PWM converter topologies are suitable for some industrial applications mentioned above because of keeping the reduced device voltage capability for wide load ranges and wider soft switching operating ranges as compared to the full bridge converter. This paper is concerned with the comparative three topologies of diode clamping, flying capacitor and diode clamping and flying capacitor hybrid DC-DC converters. In this paper, the circuit operation principles of these three-level soft switched PWM DC-DC converters, soft switching operating ranges and power regulation characteristics are evaluated on the basis of simulations and experiments from a practical point of view.