In November 2002, this initial prototype underwent static and dynamic tests and showed good performance. Energy management system and dc–dc converter adopt current control strategy. The voltage of dc BUS is decided by battery,and the output power of fuel cell is controlled through adjusting the output current by dc–dc converter, and the output power of battery is controlled indirectly by dc–dc converter, so the power distribution of the hybrid power system is effectively regulated by dc–dc converter. Fig. 9(a) is the waveforms of voltage and current of dc-dc converter transformer primary side at rated power. Fig. 9(b) is the waveform of output current when the system load is changed from 30%–100%periodically;Fig.9(c) is the converter system’s efficiency curve,which indicates that the efficiency is over 94%. dc–dc converter is over 94%, and the dynamic and static characteristic is excellent because of the digital and analog control. Experimental results prove it is suitable for commercial or residential fuel cell power supplies.