US Patent 11916389 Grid interconnection system, interconnection control device and grid interconnection method

A grid interconnection system for a power grid includes: a storage battery; a power conversion device that converts power from the storage battery into AC; and an interconnection control device that supplies power from a commercial power supply to a load and supplies power from the power conversion device to the load when the commercial power supply fails. When the commercial power supply is restored, the interconnection control device starts supply of power from the commercial power supply to the load, and stops supply of power from the power conversion device to the load after the supply of power from the commercial power supply to the load is started.