High step-up DC-DC converter with input current sharing for fuel cell applications

This paper presents a dc-dc converter for fuel cell applications based on dc-dc Forward converters with inputs connected in parallel and outputs connected in series. The advantages of the proposed topology are the high static gain, the input current sharing and the use of a unique gate signal for all the switches, although interleaving techniques can also be employed. The paper presents the operating modes, main waveforms, modeling and control strategy for the proposed converter in continuous conduction mode. In order to validate the theoretical analysis, a laboratory prototype with input voltage of 26 V, output voltage of 210 V, output power of 900 W, commutation frequency of 50 kHz was assembled and experimentally evaluated as part of a hybrid microgrid. The obtained results are presented and discussed.