| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems of a power supply unit in which a plurality of batteries such as a fuel battery and a secondary battery are connected to a load in parallel is expensive, because the fuel battery has the upper limit of an output and needs the assistance of the secondary battery, and although the secondary battery needs to be charged and must use a DC-DC converter, which meets the maximum output of the battery, and cannot improve power generation efficiency because of the internal loss of the DC-DC converter. SOLUTION: The plurality of batteries having different principles of power generation and characteristics are connected into the load parallel, a changeover switch is attached on a battery output side, the battery supplying the largest power to the load is directly connected to the load, and the other assistance batteries are connected to the load through the DC-DC converter. The battery supplying the largest power to the load is directly connected to the load, thereby preventing the internal loss caused by the DC-DC converter fro being generated, and minimizing the capacity of the DC-DC converter connected to the assistance batteries. The power supply unit which is highly efficient and inexpensive can be thus provided. |
