POWER SUPPLY SYSTEM

A power supply system includes a distributed power supply, an opening/closing switch, an impedance element, a system abnormality detection part, and a switch control part. The distributed power supply is connected to a power line for supplying power to an important load from a commercial power system. The opening/closing switch is provided on a commercial power system side of the distributed power supply. The impedance element is connected in parallel to the opening/closing switch. The system abnormality detection part detects an abnormality of the commercial power system. The switch control part opens the opening/closing switch and connects the distributed power supply and the commercial power system via the impedance element when an abnormality of the commercial rower system is detected. When the distributed power supply and the commercial power system are connected via the impedance element, the distributed power supply continues an operation including a reverse power flow.