Control of series parallel resonant converter with two different input voltage sources

Resonant DC/DC converters with dual inputs allow for two different input voltage sources. However, because of the difference of the power and control circuits of individual modules, and the coupling between modules, current circulates between the two modules. Current sharing control with voltage feedback control can be used to minimize the circulating current. Unfortunately the conventional phase shift modulation introduces different phase angle shift of the bridge voltage for different modulation levels, therefore is not suitable for the current sharing control in the dual input converter topology. We proposed a new phase shift modulation method, with which the phase angle of the bridge voltage of the resonant converter is independent of the modulation signals. The output voltage is regulated with voltage feedback control. The input difference is compensated with voltage feed forward control. Circulating current is minimized with magnitude current average control. Simulation and experiment results verified the concept.