High step-up interleaved DC-DC converter for photovoltaic systems

Abstract

This study proposes a new interleaved high step-up topology based on cross-coupled inductors and voltage multiplier cells (VMCs). Two series capacitors in VMC are employed to raise voltage gain and diminish peak voltage across switches. Thus, low voltage MOSFETs with low on-resistance (R (Formula presented.)) can be used in the proposed converter. Due to the presence of the leakage inductors in coupled inductors, the falling rate of the output diodes current is controlled and the diode recovery current problem at turn-off can be mitigated. In addition, switches are turned on under ZCS conditions which results in efficiency improvement. Using two-phase topology reduces input current ripple and shares power losses between each phase. The converter is analyzed and its operation is investigated using detailed comparisons. Finally, to confirm the performance of the proposed converter, a 30 V input voltage to 400 V output voltage prototype with the rated power of 220 W is implemented and tested in the laboratory.