A Hybrid Cascaded DC-DC Boost Converter With Ripple Reduction and Large Conversion Ratio

This paper presents a hybrid cascaded boost converter, in which the input terminal is interlaced in parallel and the output capacitors embedded in voltage multiplier cells are interlaced in series at the output terminal [input parallel output series boost converter (IPOSB)]. The IPOSB can reduce the input current ripples because two primary windings of coupled inductors are connected in parallel with the cross. The voltage multiplier units combine with diode-capacitor and coupled inductor in the output side are charged and discharged in a series and parallel way. In addition, the leakage inductance of the coupled inductor inhibits the inrush current of the capacitors. Therefore, the IPOSB can attain high gain and lower output voltage ripples under a proper duty cycle, and the leakage energy of coupled inductor can also be recycled to the load. At the same time, the voltage stress of power devices is lowered, so the low voltage level MOSFETs can be adopted to reduce the losses and cost. Meanwhile, the soft switching performance of the zero-current-switching is fulfilled, which reduces effectively switching losses. The operational principle and steady-state performance of the converter are analyzed in detail. The correctness of the theoretical analysis is verified by setting up a 450-W experimental prototype.