A power generation system includes a continuously variable transmission, a power generator, a transmission driving device, an output-side speed detector, and electric power load device, and a controller. The electric power load calculation device detects current values and current values of respective phases of three-phase alternating current generated by the power generator, calculates electric power load of the power generator based on the detected values, and executes filtering by attenuating a higher harmonic of a set frequency when calculating the electric power load of the power generator. The controller executes feedback control of calculating and outputting a gear change command to the transmission driving device so an output-side rotational speed detected by the output-side speed detector becomes equal to an output-side target rotational speed corresponding to the set frequency. The controller also executes feedforward compensation of correcting the gear change command, based on the calculated electric power load.