N-period resonant behaviour of a soft-switching push-pull converter

A soft-switching push-pull converter is researched. By insetting LC resonant elements in secondary, all power semiconductors can achieve soft-switching. The special n-period resonance mode in this converter is presented and its principle is investigated in detail. The expressions of various parameters, output voltage u_out, resonance capacitor voltage u_c and load resistor R, are derived in the n-period resonant mode. The output characteristic is described under different load resistors range. Final experiment prove the converter have the n-period resonance phenomena. The test verifies its output feature showed as a constant voltage or a constant current source by n value in turn under different n-period resonant modes.