A new single-switch soft-switched high-step up DC-DC converter based on magnetic coupling

A novel non-isolated single-switch high gain DC-DC converter is introduced in this paper. To attainment high voltage gain without using a large duty cycle, it uses a three windings coupled-inductor, a resonant capacitor, and voltage multiplier cells. This simple topology takes advantage of just one low voltage switch, continuous input current, high voltage gain capability, and high efficiency. Not only is a high voltage gain achieved but also the voltage stress of all components is reduced. Also, a passive voltage clamp is used to recover the energy stored in the leakage inductor of the coupled inductor in addition to reduce the voltage stress of the active switch. In this topology, below resonance operation mode is utilized in order to achieve higher efficiency in comparison with other high gain dc-dc converters. All the operating principles of this converter are studied to find the voltage gain and the voltage stress equations in CCM mode and steady-state. To show that the proposed converter is more beneficial than the ones designed before, their main characteristics are compared. Finally, to prove the operation of the design, the simulation results of a 30V/400V 200W converter are presented.