A dual switches high step-up DC-DC converter with low voltage stresses across switches

A dual switches high step-up DC-DC converter with coupled inductor (CI) and voltage multiplier cell (VMC) is proposed in this paper. The gate pulses of the switches are synchronized with each other. During ON state of the switches, the CIs are charged in parallel through the input power source and during OFF state of the switches, they are discharged to the output in series. The energy of the leakage inductances is recycled by the passive clamp circuit. The passive clamp circuit for one of the metaloxidesemiconductor field-effect transistor (MOSFETs) is integrated with the VMC. In such a case, the clamp circuit participates in voltage gain extension which facilitates the utilization of lower number of the components, as well. Meanwhile, the MOSFETs and diodes are turned ON and turned OFF with zero current switching (ZCS) performance which reduces the switching losses. Through the dual switches concept and implementation of the CI VMC, the advantages such as high voltage gain, low voltage stresses across switches and distributed current stresses between MOSFETs are achieved. The steady-state analysis of the proposed converter is provided which is followed by a comparison with some published converters. Finally, a 300 W 25V to 400 V laboratory prototype is fabricated and tested to verify the performances.