Design of a Trajectory Control with Minimum Energy Consumption for a Kite Power System

Abstract

A kite power system is an airborne wind energy conversion system of a ground system and the kite in altitudes of about 800–1000 m above the ground that are mechanically connected by tethers. The system generates electricity through that the circled kite pulls the tethers to drive an electrical generator installed on the ground. To keep electrical output, the kite continuously encircles under control. Hopf bifurcations were observed when the kite is in some flight postures. This phenomenon demonstrates that the kite could circle by adjusting the bridle angle. This study designed a trajectory control algorithm with minimum energy consumption via applying the dynamics of the kite. The kite firstly takes off and steadily hovers in a specific altitude under the control. Then the algorithm forced the kite into self-excitation motions which draws the tethers to rotate the generator. A simulation about the trajectory control confirms that the kite could successfully hover in an assigned altitude and then fly a limit cycle which originally exists in the kite. The controller consumes little electricity as the kite steadily flies. The use of the trajectory control with low power consumption increases the efficiency of the kite power system.