Performance Evaluation of Modified 4-Phase Interleaved Fuel Cell Converter for High-Gain High-Power Applications

This paper presents 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. The modified 4-phase interleaved fuel cell converter is studied for higher voltage conversion ratio. By virtue of paralleling the converters, the input current can be shared among the cells or phases, so that high reliability and efficiency in power electronic systems can be obtained. In addition, it is possible to improve the system characteristics such as maintenance, repair, fault tolerance, and low heat dissipation. The average-current-control in continuous conduction mode for the proposed converter is analyzed in details. The prototype fuel cell converter of 1.2-kW connected with a Nexa^TM fuel cell (1.2-kW, 26 V) developed by Ballard Power System Company is implemented for highvoltage applications. Experimental results of the power converter authenticate the excellent performance. The power converter can boost a low dc fuel cell voltage of 26 V up to a dc bus voltage of 200 V.