As a component of an aerial vehicle, a power management system having an active power control device is provided. The system includes a solar cell converting solar energy into electric energy; a fuel cell provided in the aerial vehicle and converting fuel energy into electric energy by electrochemical reaction; a battery compensating for a lack of electric power supplied from the solar cell and the fuel cell to the aerial vehicle and storing surplus electric power; and an active power control device connecting with all the solar cell, the fuel cell and the battery and combining and distributing electric power generated in the solar cell, the fuel cell and the battery to loads. The system efficiently distributes the power from the respective power sources through the controllable output of the fuel cell in accordance with power required by the aerial vehicle and the solar cell's performance depending on weather.