POWER SUPPLY SYSTEM, VEHICLE MOUNTED THEREWITH, AND METHOD OF CONTROLLING POWER SUPPLY SYSTEM

A power supply system has a power storage device (110) and an ECU (300), and supplies driving electric power to a load device (190). The power storage device (110) includes an interrupting device (CID) configured to activate where an internal pressure of the power storage device (110) has exceeded a prescribed value to interrupt a conduction path of the power storage device (110). The load device (190) includes a voltage sensor (180, 185) for detecting a voltage applied to the load device (190), and supply of electric power from the load device (190) to the power storage device (110) is stopped in response to a failure of the voltage sensor (180, 185). Where the voltage sensor (180, 185) has failed, the ECU (300) determines presence or absence of activation of the interrupting device (CID), based on a variation length of an actual current that is input to or output from the power storage device (110) and a variation length of a command current set in accordance with requested electric power requested based on a user's operation.