A new LVI assisted PSPWM DC-DC converter

In this study, a new Phase Shifted Pulse Width Modulated (PSPWM) full bridge isolated DC-DC converter is proposed. In the proposed converter, the resonant inductor is replaced with Linear Variable Inductor (LVI), and controlled with output current. The new converter has many advantages over recently developed PSPWM DC-DC converters in terms of control simplicity and efficiency. The soft switching operation range is wide and dependency of ZVS operation to the load current is low. At low current levels the required energy for ZVS operation is obtained easily because the value of LVI is large enough. The value of LVI decreases linearly with increasing current. At high current levels parasitic resonance and duty cycle loss are decreased. By selecting the range of the LVI properly, dead time control between gate drive signals of the IGBTs in the same leg is not required. A single phase 160A inverter arc welding machine is implemented with the proposed converter. The experimental results taken from the converter shows the feasibility of the proposed method.