In modern wind power plants, the power output from the wind is adapted to the changing wind conditions. In the strong wind range, power output is limited to protect the turbine. The rotor blade adjustment serves this purpose. By adjusting the angle, this changes the forces acting on the rotor blade. In the normal wind range, power consumption is optimised by means of generator systems with variable speed.
ET 210 demonstrates a wind power plant with rotor blade adjustment and generator with variable speed. The wind power plant stands on a tower in a wind tunnel. The air flow is generated by an adjustable speed fan. A flow straightener ensures consistent and low-turbulence flow. A three-blade rotor drives the generator directly.
In order to approach different operating points, the target speed of the rotor can be set. A servomotor is used to change the adjustment angle of the rotor blades. The angle between the rotor axis and the wind direction (yaw angle) can be adjusted by means of a handwheel.
The rotor speed is precisely measured by Hall sensors built into the generator. The wind velocity is measured by a horizontally adjustable wind velocity sensor, so that the average wind velocity over the rotor surface can be recorded. The yaw angle is measured by an angle sensor. The operation and control of the experimental unit is carried out via a PC (not included in the scope of delivery) with GUNT software connected via a USB interface. The network capable GUNT software makes it possible to observe, acquire, and analyse the experiments at any number of workstations via the customer’s own network with just one licence. The GUNT software calculates the converted electrical power, the generator torque and system-specific parameters.
The rotor blades can be easily replaced. The wind tunnel is closed during the experiments to ensure that the experiments are conducted safely. The interlock on the transparent protective cover and a smart shut down system that turns off the wind tunnel fan in the event that over current or over speed is detected, ensure safe operation.