Title: Quasi-Steady Model of a Pumping Kite Power System,
Abstract: The traction force of a kite can be used to drive a cyclic motion for
extracting wind energy from the atmosphere. This paper presents a novel
quasi-steady modelling framework for predicting the power generated over a full
pumping cycle. The cycle is divided into traction, retraction and transition
phases, each described by an individual set of analytic equations. The effect
of gravity on the airborne system components is included in the framework. A
trade-off is made between modelling accuracy and computation speed such that
the model is specifically useful for system optimisation and scaling in
economic feasibility studies. Simulation results are compared to experimental
measurements of a 20 kW kite power system operated up to a tether length of 720
m. Simulation and experiment agree reasonably well, both for moderate and for
strong wind conditions, indicating that the effect of gravity has to be taken
into account for a predictive performance simulation.