Coupled inductor-based DC-DC converter with high voltage conversion ratio and smooth input current'

Abstract

In this study, a coupled inductor (CI)-based high step-up DC-DC converter is presented. The proposed topology is developed from a primitive quadratic boost converter (QBC) structure. A two-phase interleaved QBC structure is obtained by employing multi-winding CIs instead of discrete inductors as the energy storage magnetic element. The voltage gain is further extended by using (i) voltage lift capacitor, (ii) CIs and (iii) voltage multiplier cells. Consequently, the voltage stress on the main switches is reduced to 18.9% of the output voltage. Moreover, interleaving mechanism helps in achieving a smooth input current profile; the input current ripple is only 4.59% of the total input current magnitude. To validate the proposed concept, 18 V/380 V, 150 W prototype converter is constructed and experimented. Under experimentation, the converter delivers the required power to the load at 95% full-load efficiency. Further, under closed-loop condition, the output voltage from the converter is regulated to the required standard value of 380 V DC.