Simulation Based Design of Kite Power Systems

64 Flavio Gohl Empa Center for Synergetic Structures Überlandstrasse 129 CH-8600 Dübendorf Switzerland flavio.gohl@empa.ch http://www.empa.ch/css

Simulation Based Design of Kite Power Systems

Flavio Gohl, Rolf H. Luchsinger Empa – Center for Synergetic Structures

A versatile simulation tool for kitepower systems is present-ed. The core of the simulator is a detailed aerodynamic mod-el of the kite based on the Vortex Lattice Method (VLM). The kite is assumed to be a rigid body while the tether is mod-eled as a flexible cable. In a multiline configuration the kite is steered by tether actuation from the ground taking e.g. the ef-fects of the line sagging on the controllability of the kite into account. The full simulation step runs in real-time. This could only be achieved by developing all the software components in-house in C++. The real-time simulation allows the user to fly the kite with a joystick, a feature we found crucial for an-alyzing and optimizing different wing designs with respect to their dynamic behavior.

In a second step, the simulation tool was extended to fly

complete pumping cycles with automatic control. Next to the simulation of the traction phase and the retraction phase, the transition between the two phases is of great interest. Espe-cially for the retraction phase and transition phases the de-tailed physical model of the presented simulator is of out-most importance. Various wing configurations, flight patterns and control strategies were studied with respect to their in-fluence on the power output of the pumping cycle kite power system. Different scenarios such as high and low wind were also considered, where the flight strategy might be adapted. Finally, the flexibility of the simulator allows the modeling of other AWE concepts such as the flying generator or the car-ousel, too. In this presentation, the potential and limitation of this simulation framework are discussed.