Design and Optimization of Friction Winch for 25 MW Airborne Wind Energy Systems

[Objective] Friction winch is the main working equipment for Airborne Wind Energy Systems (AWES). To overcome the difficulties of high cable tension, high linear velocity and complex working conditions during its operation to meet the requirements of long service life, high reliability and high safety, a floating double drum friction winch mechanism based on pressure bearing wheels is proposed. [Method] The key components of the pressure bearing wheel and drum were optimized using finite element analysis software. A force analysis model for the friction winch was established and subjected to mechanical analysis. The variable density method was used to optimize the topology of the internal support structure of the pressure bearing wheel. Parameterized modeling of the drum was conducted, followed by sensitivity analysis to screen out structural parameters with significant sensitivity to maximum stress, mean stress and geometric mass. Using the central composite experimental design method, a response surface model was established for the drum's stress, mass and main design structural parameters. [Result] By taking the minimum strain energy as the objective and the internal support volume of the pressure bearing wheel as the constraint, the optimization achieves a 36% reduction in the structural mass of the pressure bearing wheel, and its strength is verified to meet the requirements by applying loads at different locations. Sensitivity analysis is used to screen the structural parameters of the drum, and a response surface model of the drum is established for multi-objective optimization. This results in a drum optimization design that achieves a 16.6% reduction in mass while meeting strength requirements. [Conclusion] Based on finite element analysis simulation software, the key components of the friction winch are optimized and the feasibility of the above configuration was verified. This not only reduces manufacturing costs and improves economic efficiency but also addresses challenges such as bearing selection, vibration and thermal expansion in high-speed, heavy-duty winches.