Patent ID: 8362648

Claim:
An electric power supply system comprising: a DC bus line for connecting a DC generator, a load and system power with each other; a DC/DC converter connected between the DC generator and the DC bus line for controlling an output voltage to the DC bus line at a voltage V 1 ; an inverter connected between the system power and the DC bus line for outing a voltage V 2 from the DC bus line; an AC/DC converter connected between the system power and the DC bus line, for output voltage V 3 for output voltage V 3 to the DC bus line; and a storage battery connected to the DC bus line wherein when a full charge voltage of the storage battery is V 4 and an empty voltage of the storage battery is V 5 , the respective voltages are set as V 1 >V 2 >V 4 >V 3 >V 5 , and an order in which power is to be supplied to the DC bus line is automatically decided such that when a voltage of the storage battery is higher than an output voltage of the AC/DC converter, first is the DC generator, second is the storage battery and third is the system power, and when the voltage of the storage battery is lower than the output voltage of the AC/DC converter, first is the DC generator, second is the system power, and third is the storage battery.