POWER SUPPLY SYSTEM

A power supply system includes a main line, a plurality of sweep modules, and a control unit. Each sweep module includes a battery module and a power circuit module. The power circuit module switches between connection and disconnection between the battery module and the main line. The control unit executes sweep control for sequentially switching the battery modules which are to be connected to the main line. The control unit maintains connection of a refreshing module which is to be subjected to refreshing charging/discharging to the main line while sweep control is being executed in a state in which the refreshing module is excluded in at least one of outputting of electric power to the outside and inputting of electric power from the outside.