Copyright 2013 by Komel All Rights reserved
Wind power stations
Work is carried out in Komel on dissemination and utilization of renewable energy sources. We are in particular interested in wind power engineering.
Apart from manufacturing high-efficiency permanent magnet generators for wind and hydroelectric power stations, we have also designed and built a small wind power station rated at 4 kW. This was mounted on the roof of our company building in Sosnowiec, ul. Moniuszki 29 (Silesia).
Additional incentive which might tempt potential users to invest into wind power stations, is the possibility of tax reduction (construction cost may be deduced from agricultural tax, in accordance with Article 13 of “Agricultural Tax Bill” of 15th Nov., 1984, with subsequent changes).
Wind power station design
The proposed design of wind power station has been developed in our institute. The design data is:
- rated power 4 kW (at wind velocity 10 m/s),
- rotor (propeller) diameter 5.8 m,
- number of propeller blades 3,
- blade-angle setting (against the wind): rudder (principal),
- gearless system: no gear needed for increasing rotational speed,
- protection against strong winds: anti-storm system with side helm,
- generator used: PMGg 180L16 (3 kVA, 180 rpm, UN=3x170 V ->> 230 V UDC, fN=24 Hz),
1. Propellers (rotor) The propellers are made of aluminium sheet, mounted on brackets fixed to a steel pipe. The brackets are designed in such a way that assembly of the whole propeller is easy. Blade incidence angles and blade setting angles are obtained by supporting the brackets on a level foundation during assembly.
It must be emphasized that achieving proper setting angles is of utmost importance if high power is to be obtained from the wind turbine.
2. Protection against strong wind As you can observe (see illustration), the wind turbine rudder is hinged and the side rudder ensures setting the whole propeller in the direction of the wind (if the wind blows too strongly). The details are clarified in the drawing.
3. Generator and electric circuit
In order to eliminate the gear, which is both costly and unreliable (the manufacturer's price of new gear is higher than the cost of new generator, even though the gear consists of several toothed wheels only!), we have used generator PMGg 180L-16 spec. manufactured by Komel. This is a high-efficiency permanent magnet generator. If the wind power station is to operate, then permanent magnet generator must be used. This type of generator is self-excited, i.e. it generates voltage as soon as it starts to turn. The generator does not contain any brush sets, commutator etc., which is why it is highly reliable.
Since propeller's rotational speed is equal to c. 150-180 rpm with wind blowing at 10 m/s, the three-phase induced voltage will be characterized by 24 Hz frequency. The ac voltage will then be rectified into dc voltage. For wind blowing at 10 m/s we obtain dc rectified voltage equal to 230 V +/-10%. This rectified voltage may then be successfully used to supply different heaters or lighting circuits - incandescent lamps (bulbs).
Since wind power changes with wind velocity, a set of three heaters has been designed, to be switched in accordance with force of wind. One heater is permanently connected, two others are switched on in turn, when wind freshens. Contactors 1 and 2 are controlled with two-level relay.
4. Power output from the wind power station
The power is output with the help of cable (stranded wire), run inside a steel mast of 273 mm diameter and 12.5 mm wall thickness. Since the rotor does not perform too many turns around the vertical axis, there is no risk of breaking the cable. However, it is recommended to check the cable at regular intervals (e.g. once every six months) to make sure if it is not excessively twisted (there is a hole in the lower part of the mast and the cable is led out through this opening).
Our Institute tries very hard to convey information in such a way that it might be possible for any person to erect an effective and safe wind power plant. However, anybody using this information must be aware that it is done on his own responsibility. Our company accepts no liability for possible damage resulting from using information given here.
Renewable Energy Sources
Institute of Electrical Drives and Machines