20.04.2017 1 March 2006 Development and Test of a 5 kW Wind Turbine for Modular Autonomous Supply Systems Berthold Hahn Paul Kühn Institut für Solare Energieversorgungstechnik (ISET), Division Information and Energy Economy Kassel, Germany  

Development of a small wind turbine for the modular system technology 20.04.2017 2006-03-01 Development of a small wind turbine for the modular system technology Supported by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety Development and design of mechanical components Grid parallel pilot operation ISET Wind-test Testing within an autonomous supply system aerodyn SMA Micro-wind Concept study and market analysis Uni Stuttgart Uni Kassel Project management and development of the control unit Airfoil analysis Development of the generator

20.04.2017 2006-03-01 Background Modular system technology provides smart, customised decentral power supply systems, but up to now no appropriate wind turbine.  new development neccessary  intense cost pressure Objective Development of a small wind turbine that is compatible with modular electrical power systems and near to the price level of large wind turbines.  retail price < 2000 € / kW

Approach Outcome Integrated design concept,  20.04.2017 2006-03-01 Approach Outcome Integrated design concept,  load-bearing casing, passive yaw control State of the art control unit  (grid connection, monitoring and remote control) Simple electrical concept with  specially designed generator Rotor blades which are easy to  manufacture Fully enclosed nacelle protects all parts against corrosion and external media, weight and cost reduction, downwind turbine with free yaw No additional features needed when operating in autonomos supply systems, cost reduction Compatibility with modular power supply systems and conventional electrical grids, increased efficiency, cost reduction Significant cost reduction with little loss in efficiency

Technical data aeroSmart5 20.04.2017 2006-03-01 Technical data aeroSmart5 Asynchronous Generator, 2-levels Nominal Power: 5,0 kW Wind Speed Cut in: Nominal: Max. Survival: 3,5 m/s 13,5 m/s 65 m/s Power Control: Passive-Stall Yaw: Downwind with Free Yaw Number of Blades: 3 Rotor Diameter: 5,1 m Weight Nacelle with Rotor: 141 kg Brake System: Electromagnetic Safety Brake Redundant Mechanical Brake source: aerodyn Rotor blades: Pultruded glass fibre reinforced plastic (GRP) High lift to drag ratio Constant airfoil section throughout the length Not twisted, fixed angle throughout the length

Measurements (1 Hz and 60 Hz): 20.04.2017 2006-03-01 aeroSmart5 with Control Unit PV-Moduls with Inverters Battery Inverters and Battery Diesel Generator Loads Setup of the system Measurements (1 Hz and 60 Hz): Prototype of the aeroSmart5 at the ISET test facility „Alte Schanze“ Meteorological parameters at hub height Electrical current, voltage and power of all system components Yaw orientation, tower acceleration... AC-Bus

Tests focus on... ● Optimisation of the control system 20.04.2017 2006-03-01 Tests focus on... ● Optimisation of the control system reactive power compensation hysteresis loop switching between generator stages stepping procedure between generator stages brake control ● Operation of different system configurations with special emphasis on analysis of interaction between wind turbine and battery inverters ● Reaction and stability of the yaw system under turbulent wind conditions ● Investigation of dynamic processes oscillations of nacelle and tower dynamic behaviour of electrical properties fluctuation of electrical power under influence of stall effect

Battery charging effects 20.04.2017 2006-03-01 ... Battery charging effects Battery current Set value for charging voltage Charging voltage Alte Schanze – system configuration with two dump loads (1 kW and 5 kW) 1-min-average, 2005-07-20

aeroSmart5 measured power curve 20.04.2017 2006-03-01 aeroSmart5 measured power curve Alte Schanze, 10-min-data: 2005-12-01 to 2006-01-26

20.04.2017 2006-03-01 Outlook ● Optimisation of interaction between wind turbine and hybrid power system  improvement of battery charge process ● Test of single-phase model (60 Hz) for the US-American market ● Launch in 2007 ● Development of a 10 kW model