New interleaved high step-up converter based on a voltage multiplier cell mixed with magnetic devices

A high step voltage ratio converter is introduced in this study. In order to improve the voltage gain and the voltage stress of semiconductors, coupled-inductor (CI) combined with built-in transformer (BIT) and voltage multiplier cell are employed. Therefore, comparing with previously presented converters in which only CI or BIT structure was used, a greater degree of freedom is obtained. Consequently, the low voltage rated semiconductors can be utilised which in turn decrease the conduction losses. To deal with the ringing phenomenon and reverse recovery problem, zero-current switching turn-on/turn-off are well achieved for switches/diodes via leakage inductances of magnetic means. Moreover, by employing passive clamps, leakage energy is recycled. Furthermore, due to the interleaved structure, the input current ripple is considerably diminished. In addition, the share of input current between different phases is equitable as a result of the charge balance of capacitors. With all these in mind, the proposed structure is a good candidate for high current and high power applications. Finally, in order to validate the effectiveness of the proposed topology, a 600W 24V/480V laboratory prototype is fabricated.