Patent ID: 8310094

Claim:
A power supply system comprising: a DC power supply string in which a storage battery module is connected in parallel to a DC power supply; a DC/AC power conversion device for connecting the DC power supply string to a power system or a load; and a switch, connected between the DC power supply and the storage battery module, for switching an output power of the DC power supply when the switch is ON or OFF or a combined output power of the DC power supply and the storage battery module when the switch is ON and supplying to the DC/AC power conversion device, wherein the DC power supply is a solar battery module, and the DC power supply string is a solar battery string, wherein the DC power supply string includes a time monitoring unit, a voltage detecting unit, or a current detecting unit, wherein the switch is switched when one of the time monitoring unit, the voltage detecting unit, or the current detecting unit satisfies a predetermined condition, and wherein the predetermined condition is i) start output (switch ON) when a detected voltage of the voltage detecting unit or a detected current of the current detecting unit becomes greater than or equal to a predetermined value, or stop output (switch OFF) when becoming smaller than or equal to the predetermined value, ii) start output (switch ON) or stop output (switch OFF) in accordance with a predetermined time of the time monitoring unit, iii) start output (switch ON) or stop output (switch OFF) when the detected voltage of the voltage detecting unit or the detected current of the current detecting unit becomes greater than or equal to the predetermined value and in accordance with the predetermined time of the time monitoring unit, and iv) start output (switch ON) or stop output (switch OFF) when the detected voltage of the voltage detecting unit or the detected current of the current detecting unit becomes smaller than or equal to the predetermined value and in accordance with the predetermined time of the time monitoring unit.