Abstract
This paper proposes a novel DC-DC converter for a hybrid power supply using both a fuel cell and battery. The output voltage is controlled by a series converter that regulates only the differential voltage between the fuel cell and the output. Although the output power changes, the variation in the fuel cell current is suppressed by using a battery for the operation of the parallel converter. The control strategy and circuit design adopted to achieve high efficiency are described in this paper. The experimental results confirm that the proposed circuit achieves a maximum efficiency of 98.8% for a small differential voltage. In addition, the power loss is analyzed to prove the validity of the proposed circuit.
