POWER MANAGEMENT SYSTEM

A power management system manages power transmitted between a VPP connected to a power network installed in a predetermined area and the power network. The VPP includes vehicles each including a power storage device that is chargeable by receiving power from the power network. A server of the power management system acquires the state of a relay for each of the vehicles. When number of on times that the relay is brought from a disconnected state to a connected state is more than a first value in a case that the power storage device is charged in a target vehicle in accordance with a request for an increase in amount of power demanded in the power network, the server instructs the target vehicle to maintain the relay in the connected state until a charge process executed in accordance with the request is completed.