Current-fed push-pull converter is suitable for low-voltage input high-voltage output applications. However, the traditional topology has some limitations such as hard-switching, high switching loss, high voltage stress and high turns ratio of transformer. Regarding these drawbacks, one new interleaved zero-voltage-switching (ZVS) current-fed push-pull converter is proposed in this paper, where a simple active-clamping circuit is introduced to realize ZVS for all primary switches and recycle the energy stored in the leakage inductance. Also, the input-parallel output-series solution is used to reduce the current-stress across switches, voltage-stress on secondary diodes, filter size and transformer turns ratio. The operation principle and key design are discussed in this article and finally, one 800W experimental prototype has been built and results verified the effectiveness of the proposed circuit.
