How The Turbine Works?
Description of Hannevind Turbines
The 5.5kW to 45kW wind turbines utilise a motor and aerometer instead of a tail to follow the wind direction.
The wind turbines are three bladed and attached to the gearbox’s main axle via a hub which was developed by
Swedish Manufacturers Hannevind. The generator is asynchronous, meaning that when a power interruption occurs,
the wind turbine loses its magnetism and therefore its ability to deliver power. This protects the ESB line
engineers from turbine generated power, in the event of an outage. This also causes the brakes to activate
and prevents the turbine from overrunning and causing damage. Apart from power interruption there are additional
protections which stop the turbines when, for example, imbalance or storms occur.
During normal operation, in wind velocity up to 10-12 m/s, the turbine performs normally, and when the
wind increases over these values it is yawed out of the wind approximately 45 degrees, but continues to
deliver power. In this situation, the wind is measured at 15 minute intervals and if peaks exceeding the
specified values continue to be measured, the wind turbine remains in this position.
If the wind however decreases the wind turbine is yawed towards the wind again.
At a wind velocity over 18-20m/s the wind turbine is yawed 90 degrees out of the wind and is shut down via the
braking mechanism. This is control, led by a computer which is preprogrammed for standard wind conditions,
but can also be easily adjusted to customer specific parameters.
The energy surpluses produced, can be used to heat water or can be sold to your electricity supplier.
The wind turbines are always connected on the customer’s side of the electricity metre.
As soon as the rotor reaches the correct rotating speed, it begins to deliver electricity
proportional to the wind velocity.
Detailed Description
The asynchronous generator is a squirrel cage induction motor. When all the conditions are met,
the controller allows the motor to ramp up to synchronous speed. During this stage the machine has a negative "slip". The slip
becomes positive above system synchronous speed and increases as the input wind speed/power increases. The controller keeps the turbine
on the rising edge i.e. between + 0.06 to + 0.08, the stable portion as shown in the graph below.
Hannevind Turbines - Sweden
Click on the link below to visit the Hannevind manufacturers website
Visit Hannevind Website