This study presents a new isolated DC/DC converter of full‐bridge to connect a fuel cell to DC bus in a hybrid distribution generation system. This converter consists of a high‐frequency transformer and a voltage booster circuit. The circuit has been designed and each isolated‐gate bipolar transistor (IGBT) presents soft‐switching during the whole power range of the converter. The switching losses of the IGBTs, the reverse‐recovery losses of all of the diodes, and the core losses have almost been eliminated. To improve the efficiency, transformer cores and inductors have been built with material nanocrystalline. The efficiency is improved if this is compared with that of a conventional zero‐voltage switching converter. Also, this converter can obtain a high‐voltage gain and medium and high DC power can be converted. The analysis and switching techniques have been reported. Finally, to verify the principle of operation, a laboratory prototype of 2 kW has been performed.