POWER SYSTEM CONTROL METHOD, POWER SYSTEM CONTROL DEVICE, AND POWER SYSTEM CONTROL PROGRAM

Based on a predicted value of power demand and a predicted value of the generated power of a power generation system using a natural energy, this power system control device determines the generated power of a fuel cell system in the future so that the sum of the fluctuation of the generated power of the fuel cell system, the purchased power from a power grid, and the reverse power flow power to the power grid becomes the minimum region, and outputs a command for controlling the fuel cell system so as to output the determined generated power.