A parallel soft-switching push-pull converter applied in automotive inverters

A parallel technique with a coupled inductor is proposed for an LCL resonant push-pull converter. The coupled inductor is inserted in the front of the common resonant capacitor of two parallel soft-switching push-pull converters to share the load currents of the two converters. The equivalent circuit and state equation of the proposed converter is described, and then the effect of the mismatch of the equivalent resistor and leakage inductor on current-sharing degree is derived. Experimental results of a 2kW inverter showed that the current difference of the two parallel units is less than 2%.