Working of Different Type of Horizontal and Vertical Axis Small Wind Turbine
[A] Small Wind Turbines - Horizontal Axis Wind Turbine (HAWT)
- Its use is universal In most of the countries.
- Following Figure A shows the sequential connections of the components for such wind turbine small plant.
1. Turbine rotor with blades
2. Electromagnetic brakes
3. Mechanical brakes
4. Gear box
5. Generator
6. Flap/ Tall vane
7. Tower top
8. Shaft
9. Controller
10. Tower
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| Figure A |
Blades of Horizontal Axis Wind Turbine :
- Made of wood for low capacity, high density glass fibre reinforced plastic of aerofoil section.
- Blades are assembled on hub. Turbine shaft is provided with good quality bearing for easy rotation.
- Assembly of all above components is mounted at the top of the tower. All weights are supported by heighted steel tower well founded in the soil and foundation.
- The box housing the main parts like hub, brakes, generator, gear box and electric controls are accommodated in a closed box-type cover called as Nacelle.
- For automatic operations, electromagnetic brakes are used.
- To keep nacelle facing the wind, yaw control mechanism is provided.
- Flap/ tail vane helps in positioning of the turbine axis with wind direction.
- Blade-rotor-turbine assembly gets adjusted with wind facing-wind power drives the rotor of the turbine. Through gear box, mechanical energy is received by the generator.
- Generator converts mechanical energy into electrical energy. The power output matches with the frequency of grid frequency and power can be fed to the grid system.
It has the following main components and parts of Vertical Axes Wind Turbine :
- Blades
- Shaft
- Bearings
- Lower platform
- Upper platform
- Gear box
- Generator
- Disc brakes
- Foundation
- Guyropes
- Cross arms
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| Figure B |
- In the top and bottom bearing, the vertical shaft (2) is supported.
- Support for lower bearing-foundation
- Suppur for upper bearings-6 guyropes.
- Tower height-100 m. At the top and bottom the blades are attached to the rotor shaft.
- The blade section is aerofoil.
- Turbine vertical shaft is coupled to the generator shaft through gears (Gear Box).
- Disk brakes are provided.
- Turbine as well as generator also operate on variable speed.
- Running tip-speed ratio is very large in this case.
Energy Conversion (Input to Output) :
Wind energy rotates the blades of turbine-Turbine rotor starts rotating, through gear box the mechanical energy of rotor of the turbine is transferred to the generator. Generator converts this mechanical energy into electrical energy.