Analysis of DC/DC converters with resonant filters

Conventional DC/DC power converter topologies contain a single semiconductor switch, a diode and various arrangements of inductors and capacitors to filter the resulting waveforms into low ripple DC. The output or input voltage is limited to the rating of the semiconductor switch and diode. For high voltage performance, transformers are added to form forward, flyback or push-pull topologies. For high input voltages, semiconductor switches are arranged in an inverter bridge topology with a transformer to operate at higher voltages. Generally, conventional DC/DC power converters are limited to low voltage applications. The addition of a transformer to provide sufficient voltage gain adds significant weight to the converter. Series, parallel resonant circuits with dual bridge circuits can function like a DC/DC power converter with a transformer. Resonant converter topologies concepts have existed for the past 30 years. This paper presents a simplified generalized view of resonant circuits as π-filters and T-filters which give insight into improving circuit performance and developing new resonant topologies for bidirectional power flow