POWER CONTROL SYSTEM, POWER SUPPLY INSTRUCTION SYSTEM, AND POWER CONTROL METHOD

Voltage in a power transmission-distribution system is managed by calculating a power control amount of a distributed energy resource in consideration of the whole power transmission-distribution system. A power control system includes: a power distribution system contraction unit contracting the power distribution system including the distributed energy resource in a point of a power transmission system using control power amount range, and calculating a contraction control power amount range; a contraction power amount calculation unit calculating a contraction power amount to satisfy the contraction control power amount range based on a power transmission system evaluation value; a power control amount calculation unit calculating a power control amount controlled by the distributed energy resource based on the contraction power amount and a power distribution system evaluation value; and a communication unit transmitting the power control amount to the distributed energy resource.