POWER CONVERSION DEVICE, CONTROL DEVICE, SERVER AND SYSTEM

A power conversion device which converts electrical power generated by a distributed energy resource into electrical power corresponding to a power system is provided, comprising a communication unit which periodically receives, via communication, reception information indicating whether an accident has occurred in the power system, a disconnection unit which disconnects the distributed energy resource from the power system when the communication unit receives the reception information indicating accident occurrence, and a control unit which starts an islanding determination process for determining whether the distributed energy resource is in an islanding state by detecting a change in AC characteristics in the power system, when the communication unit does not receive the reception information for a predetermined first period.