Major Parts Of Wind Turbine
Tower of wind turbine
Tower is very crucial part of wind turbine that supports all the other parts. It is not only support the parts but raise the wind turbine so that its blades safely clear the ground and so it can reach the stronger winds at higher elevations. The height of tower depends upon the power capacity of wind turbine. Larger turbines usually mounted on tower ranging from 40 mtr to 100 mtr.
Nacelle of wind turbine
Nacelle is big box that sits on the tower and house all the components in a wind turbine . It houses power converter, shaft,gearbox , generator,turbine controller , cables ,yaw drive.
Rotor blades of wind turbine
Blades are the mechanical part of wind turbine that converts wind kinetic energy into mechanical energy. When the wind forces the blades to move , it transfers some of its energy to shaft. Blades are shaped like airplane wings blades can be as long as 150 feet.
Shaft of wind turbine
The shaft is connected to the rotor . when the rotor spins , the shaft spins as well. In this way the rotor transfers its mechanical energy to shafts which enters to an electrical generator on the other hand .
Gearbox
The rotor turns the shaft at low speed ex. 20 rpm but for generator to generate electricity we need higher speed. gearbox increases the speed to much higher value required by most generator to produce electricity .
Generator
Generator is electrical device that convert mechanical energy received from shaft into electrical energy . It works on electromagnetic induction to produce electrical voltage or current . A simple generator consists of magnets and a conductor .The conductor is typically a coiled wire. Inside the generator shaft connects to an assembly of permanent magnets that surrounded by magnets and one of those parts is rotating relative to the other , it induce the voltage in the conductor . When the rotor spins to the shaft , the shaft spins the assembly if magnets and generate voltage in the coil of wire.
Power converter
Because wind is not always constant so electrical potential generated from generator is not constant but we need a very stable voltage to feed the grid . Power converter is an electrical device that stabilizes the output alternating voltage transferred to grid.
Turbine controller
Turbine controller is a computer (PLC) that controls the entire turbine . It starts and stops the turbine and runs self diagnostic in case of any error in the turbine .
Anemometer
It measures the wind speed and passes the speed information to PLC to control the turbine power .
Wind vane
It senses the direction of wind and passes the direction to PLC then PLC faces the blades in such a way that it cuts the maximum wind .
Pitch drive
Pitch drive motors controls the angle of blades whenever wind changes it rotates the angle of blades to cut the maximum wind , which is called pitching of blades .
Yaw drive
Blades and other components in wind turbine is housed in nacelle,whenever any change in wind direction is there nacelle has to move in the direction of wind to extract the maximum energy from wind. for this purpose yaw drive motor are used to rotate the nacelle . it is controlled by PLC that uses the wind vane information to sense the wind direction .
When the wind strikes the rotor blades , blades start to rotating , rotor is directly connected to high speed gearbox . gearbox converts the rotor rotation into high speed which rotates the electrical generator . an exciter is needed to give the required excitation to the coil so that it can generate required voltage . the exciter current is controlled by a turbine controller which senses the wind speed based on that it calculate the power what we can achieve at that particular wind speed . then output voltage of electrical generator is given to a rectifier and rectifier output is given to line converter unit to stabilise the output ac that is feed to the grid by a high voltage transformer. an extra units is used to give the power to internal auxiliaries of wind turbine (like motor, battery ) , this is called internal supply unit ISU. can take the power from grid as well as from wind , chopper is used to dissipate extra energy from the RU for safty purpose ,