Interleaved high step-up DC-DC converter based on voltage multiplier cell and voltage-stacking techniques for renewable energy applications

A novel interleaved high step-up DC-DC converter based on voltage multiplier cell and voltage-stacking techniques is proposed for the power conversion in renewable energy power systems. The circuit configuration incorporates an input-parallel output-series boost converter with coupled inductors, clamp circuits and a voltage multiplier cell stacking on the output side to extend the voltage gain. The converter achieves high voltage conversion ratio without working at extreme large duty ratio. The voltage stresses on the power switches are significantly lower than the output voltage. As a result, the low-voltage-rated metal-oxide-semiconductor field-effect transistors (MOSFETs) can be employed to reduce the conduction losses and higher conversion efficiency can be expected. The interleaved operation reduces the input current ripple. The leakage inductances of the coupled inductors act on mitigating the diode reverse recovery problem. The operating principle, steady-state analysis and design guidelines of the proposed converter are presented in detail. Finally, a 1-kW prototype with 28-V input and 380-V output voltages was implemented and tested. The experimental results are presented to validate the performance of the proposed converter.