An apparatus for controlling power generation of a generator has a voltage detector and a power controller. The voltage detector detects a voltage of electric power generated in the generator. When receiving a first power control signal, the power controller controls the generator to maintain the detected voltage at a first target value. When receiving a second power control signal, the power controller controls the generator such that the power controller suppresses the power generation of the generator based on a difference between a value of the detected voltage and a second target value lower than the first target value so as to maintain the detected voltage at a predetermined value lower than the first target value. Therefore, even when the power generation is suppressed, pulsation of the generated electric power can be appropriately restrained.