Modified 4-phase interleaved fuel cell converter for high-power high-voltage applications

This paper proposes a modified 4-phase paralleled step-up converter for fuel cell generator. In high power applications, the interleaving technique for paralleling input of the converter system has been studied for many years. Since component parasitic elements limit the practically realizable voltage-gain of any converter topology, this becomes a critical issue in the case of the classical step-up converter. The modified 4-phase interleaved fuel cell converter is studied for higher voltage conversion ratio. Since the fuel cell current is proportional to the fuel (hydrogen and oxygen) input, it is obligatory to have a fuel cell current control loop, in order to limit a high current transition of fuel cell to prevent the fuel starvation phenomenon. The average-current-control in continuous conduction mode for the proposed converter is analyzed in details. Classical PI controllers are selected for each current control loop. The fuel cell converter of 40-kW is studied for high power high voltage applications. Experimental and simulated results of the power converters authenticate the excellent performance of the studied fuel cell converter.