Improving winch control performance in Kite Power Systems using gain scheduling and a compliant element

Improving winch control performance in Kite Power Systems using gain scheduling and a compliant element

Schreuder, E.N.J.

Babuska, R. (mentor)
Lopes, G.A.D. (mentor)
Fechner, U. (mentor)

Electrical Engineering, Mathematics and Computer Science

DCSC

Embedded Systems

2013-12-12

Rising demands in energy consumption necessitate the development of low-cost renewable power generation. A Kite Power Sytem (KPS) is a novel approach to harvest wind energy with kites at higher altitudes than is possible with conventional wind turbines, at a lower cost. In this thesis, an approach to improve the winch controller of a KPS will be proposed in order to increase the power output. Measurements of the test system revealed an especially poor performance during the reel out phase, where the tether force was constrained to a maximum. It was found that a propagation delay is present on the system input. A force tracking controller for the reel out phase therefore needs to be developed, which accounts for the system’s propagation delays. A nonlinear KPS model that can be used in control algorithm design was presented. To control the nonlinear system across its full operating region, a gain scheduled feedback controller was proposed. It was found that the stability of the modeled original system was compromised when the system delay is high enough. By extending the system with a compliant element, a larger delay can be allowed before instability occurs. Within the boundary conditions of the nonlinear KPS model, by applying gain scheduled feedback control with integral action and extending the system with a compliant element, the winch controller can asymptotically track a force reference across its operating region in case of system delays. Given that the correct force reference is supplied, this will increase the power output of the KPS.

kite power
airborne wind energy
gain scheduling
winch control
compliant element

http://resolver.tudelft.nl/uuid:265aa8d7-7ccf-4257-a22b-ff94b8fe4556

2016-12-04

Student theses

master thesis

(c) 2013 Schreuder, E.N.J.