Important Points about Wind Power Plants
Principle of Wind Power : Kinetic energy of the wind is utilized to produced shaft power which in turn rotates the generator and generator converts the mechanical rotational energy into electrical energy.
The sub-components of the wind mill are :
- Wind turbine or rotor
- Windmill head
- Transmission and control
- Supporting structure
Rotor : Rotors are mainly of two types :
- Horizontal axis rotor, and
- Vertical rotor.
Direct Drive Wind Power Plant : This is the horizontal was wind power plant. The type reliable and gives better performance as compared with the first type red wind type (i.e. geared wind type).
Generator performance is improved by different provisions such as :
- Yow control : Helps in continuous adjusting the position in the direction of wind
- Pitch control : It changes blade positions with respect to wind speed.
- Stall control : It helps installing the blades when wind speed increases. They operate in safety limits.
Main components of wind power conversion to electric power :
- Blades and turbine rotor.
- Gearbox
- Induction generator
- Rectifier/Inverter unit (DC transmission link).
Main components of WRSG :
- Blades and wind turbine
- Wound rotor synchronous generator
- Exciter
- Rectifier (Generator side control)
- Inverter (Grid side control)
- 3 phase step up transformer
- Output to grid system
- D.C. link
Main components of PMSG :
- Blade and turbine rotor assembly.
- Permanent magnet synchronous generator.
- Power converting unit rectifier and inverter.
- 3 phase step-up transformer from which 3 phase A.C. power is fed to grid.
- Blade turbine assembly (1) is rotated by wind power. The rotation of steam turbine rotor gives mechanical power to generator, (2) for converting into electric power.
- Pitch angle : Angle between the direction of wind and direction perpendicular to the planes of blades.