High Gain Multi-Input DC-DC Converter with Combined Phase-Shift/PWM Modulation for Stand-Alone Applications

The objective of this paper is to introduce a new multi-input converter for a hybrid supply system containing photovoltaic, fuel cell, and battery for medium power applications. In this converter, the current ripple of fuel cell is removed, due to the utilization of a coupled inductor. Since, a combination of the magnetizing and the leakage inductors of two boosting transformers are used, a soft switching condition exists for semiconductors. To improve the reliability of the system, three switch-legs are used which results in distributed power transfer and increases the system redundancy from the reliability point of view. The steady state model and control system are discussed for the proposed converter. At the high voltage side of converter, two transformers are connected in series to achieve high voltage gain. An experimental prototype has been designed and examined in the laboratory to evaluate the proposed converter performance.