e-kite 50 kW ground station (17 April 2014).
Alfred van den Brink Co-founder and CTO e-kite Netherlands B.V. Barnseweg 65 3771 RN Barneveld The Netherlands a.vandenbrink@e-kite.com www.e-kite.com
Design of the e-50 Ground Station
Alfred van den Brink e-Kite Netherlands B.V. e-Kite is a new player in the AWE industry and founded
in 2013 by a team with a strong background in the de-velopment of direct drive wind turbines. The main fo-cus of development is a commercially viable two-line kite power system with a robust 50 kW ground station and a lightweight wing. A high energy extraction efficiency is achieved by implementing a pumping cycle with en-ergy production phase, efficient reel-in process and us-ing a direct drive generator. Because of its mobile ground station, the kite power system is particularly suitable for companies and farmers in remote locations, army, festi-vals, etc. Since the kite altitude is not exceeding 100 m the system can be operated in compliance with current airspace regulations. A high safety level is achieved by us-ing two traction cables and implementus-ing a robust steer-ing mechanism at the ground.
At the core of the ground station is an an efficient direct drive generator with electrical field excitation and inte-grated differential steering system. This system is located in the generator rotor and mechanically connected to the two traction cable pulleys. A high reliability is achieved
by using industrial grade components which have proven to work well in the wind industry. A full back-2-back con-verter controls both generator and grid connection. An industrial controller is used with a robust sensor/actuator network. The complete ground station can rotate and po-sition itself towards the kite by an integrated yaw system. Cable spooling is realized by a robust system with mini-mal pulley guidance and targeting to reduce tether wear. All systems (i.e. generator control, control system, kite, steering, yaw, cable spooling etc.) are tested against de-sign specification and fully operational.
A fully automated system is foreseen for vertical launch-ing and retrieval of the kite to support autonomous op-eration. Field testing is ongoing since Q3 2014 at a dedi-cated test location in Lelystad, The Netherlands. Several milestones are passed so far for first energy production and longer than 1 hour autopilot flight.
The next steps in system development include achieving a 24 hour autopilot control, upscale the rigid wing kite ca-pable of producing 50 kW rated power and implement the new vertical launching & landing system.
