A new dual-bridge soft switching DC-to-DC power converter for high power applications

This paper has presented a dual bridge high current DC-to-DC converter with soft switching capability. The proposed dual bridge power supply is based on the two switch isolated forward converter. Unlike conventional dual bridge forward converters, phase shift control is employed to regulate the output voltage and achieve soft switching. Coupled transformers are utilized to achieve and maintain soft switching for the main devices over a wide load range. The availability of two switching bridges provides the capability of connecting the two bridges in parallel for low line voltages (230 Vac) and in series for high line voltages (460 Vac). This allows the use of low voltage rated switching devices for both low and high line applications. Furthermore, due to the bipolar excitation of the high frequency power transformer, the input capacitors are automatically balanced when the two bridges are connected in series