Kitepower is a start up that generates energy using kites. The Kitepower system consists of airborne components, and a ground station where a drum is connected to a generator/electrical motor. For generating energy a so called pumping cycle is performed. In a pumping cycle energy is generated during the traction phase when the kite pulls the drum, and some of this generated energy gets consumed during the retraction phase when the kite is reeled in. The net energy is stored in a rechargeable battery pack. In this thesis a model and a control is derived for the ground station of the Kitepower system, for the purpose of making physically realistic simulations. The Kitepower system is divided into a kite system and a ground station system. For the kite system already a proper quasi-steady model exists, but in order to do simple kite simulations and analyses a simplified version of this kite model is derived in chapter 3. In chapter 4 a ground station model is derived by using basic physical concepts and in chapter 5 a velocity and a force control are proposed for the ground station model. The derived ground station model and controls are implemented with Python, and incorporated in the kitepower software in order to make simulations of a full pumping cycle. In the result chapter 6 simulations are being done with and without using the ground station model. Both the proposed velocity and the force control are used for the simulations. The simulations are compared on physi- cally realistic behavior and validated with experimental data.