Patent ID: 7439631

Claim:
A hybrid power supply system, comprising: system voltage lines which are connected to a load; an energy type power supply device connected to the system voltage lines; a power type power supply device connected to the system voltage lines; system voltage control means having a voltage controller that change the voltage of the power type power supply device by changing the voltage of the system voltage lines, and thus allow electric power to be outputted from the power type power supply device to the system voltage lines and electric power to be absorbed by the power type power supply device from the system voltage lines; an additional energy type power supply device which is provided separately from the energy type power supply device in order to supply electric power to an input terminal of the voltage controller; and a power supply defect detector that detects a defect in the electric power supply capacity of the energy type power supply device, wherein, when the defect is detected by the power supply defect detector, the system voltage control means disconnects the defective energy type power supply device from use so that the output voltage of the voltage controller then operates under the electric power from the additional power supply device that is applied to the system voltage lines directly.