High Step-up Coupled-inductor-based Converter Using Bi-direction Energy Transmission

In this study, a high step-up converter with coupled-inductor by way of bi-direction energy transmission is investigated. In the proposed strategy, a coupled inductor with a lower-voltage-rated switch is used for raising the voltage gain whether the switch is turned on or turned off. Moreover, a passive regenerative snubber is utilized for absorbing the energy of stray inductance so that the switch duty cycle can be operated under a wide range, and the related voltage gain is higher than other coupled-inductor-based converters. The capacity of the magnetic core can be utilized completely by way of bi-direction energy transmission. In addition, all devices in this scheme also have voltage-clamped properties and their voltage stresses are only related to the output voltage. Thus, it can select low-voltage low-conduction-loss devices, and there are no reverse-recovery currents within the diodes in this circuit. Some experimental results via an example of a proton exchange membrane fuel cell (PEMFC) power source are given to demonstrate the effectiveness of the proposed power conversion strategy