Tobias Schneiderheinze Scientific Assistant Chemnitz University of Technology
Reichenhainer Straße 70 09126 Chemnitz Germany tobias.schneiderheinze @mb.tu-chemnitz.de www.lastspitzenkompensation.de www.innozug.de
High Performance Ropes and Drums In Airborne Wind Energy Systems
Tobias Schneiderheinze, Thorsten Heinze, Markus Michael Chemnitz University of Technology
The generation of electrical power from wind energy is one of the key aspects of the green energy revolution in Europe. The effectiveness of wind energy systems is di-rectly associated to the height where the energy of the wind is transformed. With increasing altitude, the ve-locity of the wind and thus the convertible amount of wind energy into electricity is increasing exponentially. Whereas conventional wind turbines reach their techni-cal limits in heights exceeding 200 m, airborne wind en-ergy systems can be used significantly above this height levels. Since almost all the systems are ground-based systems, the strength-mass-ratio of the tension members used as a support, control or pull cord plays an essential role in the flight characteristics and the efficiency of these systems.
Nowadays a variety of polymer ropes and different rope designs is already in use because of the known advan-tages of fibre ropes, e.g. low weight and high load ca-pacity, good bending flexibility and good corrosion re-sistance in comparison to steel wire ropes. In addition to these properties, modern textile mechanical compo-nents from high-strength, high-modulus polymer fibres
offer even more positive features and set-ups that can raise the capabilities and the potential of airborne wind energy systems to a higher level.
The paper illustrates the different fibre materials and de-sign options of fibre ropes and their optimisation poten-tial by following processing steps e.g. lubricating, wax-ing, stretching and heat-setting. At the same time it will be shown how ropes can be purposefully adjusted to spe-cific requirements. Some examples are weight optimiza-tion and increasing of the lifting capacity, increasing of the resistance to weather conditions as alternating high and low temperatures, humidity, water and ice, salt (and salt crystals) as also UV irradiation.
In addition, the winding properties of the rope are also of outstanding importance. The dynamic tensile load, Hertzian stress and friction occurring on the winch are placing new demands on the fibre ropes, and are influ-enced by the winch-system to a large extent. It will also be shown, which tests are to be performed for gathering tar-geted information on the winding performance and thus help to adapt the design of winches for use with fibre ropes.
