Post on 14-May-2015
description
First, let’s answer a very important question.
What are Wind Turbines?
What are Wind Turbines?
Wind turbines are devices that convert the wind’s kinetic energy into mechanical energy.
What are Wind Turbines?
If it further converts the mechanical energy to electricity, then we call it a wind generator.
WARNING!
WARNING!For convenience, whenever you see the word “wind turbine” after this slide, it will refer specifically to a wind generator.
Wind turbines have a variety of shapes and sizes…
But they’re all composed of the same 3 basic parts.
Basic Parts
A. Rotor Blades
Basic Parts
A. Rotor Blades
Basic Parts
A. Rotor Blades
B. Shaft
Basic Parts
A. Rotor Blades
B. Shaft
Basic Parts
A. Rotor Blades
B. Shaft
C. Generator
Basic Parts
A. Rotor Blades
B. Shaft
C. Generator
Basic Parts
A. Rotor Blades
The rotor blades are the “wind catchers” of a wind turbine.
Basic Parts
A. Rotor Blades
They’re long projections that have aerodynamic designs.
Basic Parts
A. Rotor Blades
When wind passes, it forces these rotor blades to turn.
Basic Parts
B. Shaft
The shaft is a rod that connects the rotor blades to the generator.
Basic Parts
B. Shaft
Its main purpose is to transfer the rotational mechanical energy of
the rotor blades to the generator.
Basic Parts
C. Generator
3 Basic Parts
Finally, the generator is a device designed to convert mechanical
energy into electrical energy.
C. Generator
3 Basic Parts
It uses the principle of electromagnetic induction.
Now that you know its basic parts, let’s understand how
wind turbines generate electricity.
Basic Processes
Basic Processes
A. Capturing Wind Energy
Basic Processes
B. Converting to Electricity
A. Capturing Wind Energy
Basic ProcessesA. Capturing Wind Energy
Basic ProcessesA. Capturing Wind Energy
Wind energy is captured using the wind turbine’s rotor blades.
Basic ProcessesA. Capturing Wind Energy
Wind energy is captured using the wind turbine’s rotor blades.
Basic ProcessesA. Capturing Wind Energy
When wind passes through the blades, two aerodynamic forces are at work.
Basic ProcessesA. Capturing Wind Energy
Rotor Blade
Basic ProcessesA. Capturing Wind Energy
LIFT
Rotor Blade
Basic ProcessesA. Capturing Wind Energy
LIFT
DRAG
Rotor Blade
Basic ProcessesA. Capturing Wind Energy
These two forces cause the rotor blades to turn, depending on how
much force the wind exerts on them.
Basic ProcessesA. Capturing Wind Energy
The process converts the wind’s kinetic energy to mechanical energy
(turning of rotor blades)
After this, it’s time to convert the mechanical energy into electricity.
Basic ProcessesB. Converting to Electricity
The turning of the rotor blades would simultaneously cause the shaft to turn,
which is connected to a generator.
Basic ProcessesB. Converting to Electricity
When the rotor blades
turn,
Basic ProcessesB. Converting to Electricity
When the rotor blades
turn,
Basic ProcessesB. Converting to Electricity
the shaft also turns.
Basic ProcessesB. Converting to Electricity
the shaft also turns.
Basic ProcessesB. Converting to Electricity
Which makes the generator
produce electricity!
Basic ProcessesB. Converting to Electricity
Which makes the generator
produce electricity!
Basic ProcessesB. Converting to Electricity
In this process, the rotational mechanical energy of the shaft is
converted to electricity by the generator.
Thanks to technology,modern wind turbines
have a host of other features
that help in solving some other problems.
Other Processes Involved
Increasing RPM
Other Processes Involved
Increasing RPM
Other Processes Involved
You might notice that large wind turbines turn slowly.
Increasing RPM
Other Processes Involved
On average, their rotor blades rotate at a speed of 20 rpm
(rotations per minute).
Increasing RPM
Other Processes Involved
20 rpm is too slow to power up a generator!
Increasing RPM
Other Processes Involved
Large wind turbines use a gearbox to increase the rpm from 20 rpm
to as much as 2000 rpm!
Increasing RPM
Other Processes Involved
To understand the process, let’s examine these two gears:
Other Processes Involved
Gear A
Gear B
Increasing RPM
Other Processes Involved
Gear A
Gear B
Gear A has 9 gear teeth
Increasing RPM
Other Processes Involved
Gear A
Gear B
Gear A has 9 gear teeth
while Gear B only has 6.
Increasing RPM
Other Processes Involved
Gear A
Gear B
Gear A has 9 gear teeth
while Gear B only has 6.This would mean that 1 revolution
of Gear A would be equal to 1.5 (9÷6) revolutions for Gear B.
Increasing RPM
Other Processes Involved
Gear A
Gear B
Gear A has 9 gear teeth
while Gear B only has 6.So if Gear A revolves at a rate of
20 rpm, Gear B would revolve at a faster rate of 30 (20×1.5) rpm.
Increasing RPM
Other Processes Involved
In large wind turbines, they use a variety of gears (hence the name,
gearbox) to multiply the rpm of the shaft.
Increasing RPM
Yaw Adjustment (HAWT only)
Other Processes Involved
HAWTs (horizontal-axis wind turbines) should be directed the same direction as the wind to
maximize the energy collected.
Other Processes Involved
Wind direction isn’t constant though,
Yaw Adjustment (HAWT only)
Other Processes Involved
So modern HAWTs use a yaw-adjustment system
Yaw Adjustment (HAWT only)
Other Processes Involved
To position the rotor blades in the correct direction.
Yaw Adjustment (HAWT only)
Other Processes Involved
The system usually consists of a sensor to monitor wind direction
Yaw Adjustment (HAWT only)
Other Processes InvolvedYaw Adjustment (HAWT only)
and a motor to adjust turbine direction.
Braking Mechanism
Other Processes Involved
Finally, there are places where wind speeds can reach extremely
high levels.
Braking Mechanism
Other Processes Involved
Overspeeding of the rotor blades can cause malfunctions on the
wind turbine’s system.
Braking Mechanism
Other Processes Involved
This is why a braking mechanism should exist to limit the maximum
speed of the rotor blades.
Image Credits
Slide # Source
1 http://www.flickr.com/photos/hddod/141018304/
9
http://www.flickr.com/photos/stuartwildlife/3451992116/
http://www.flickr.com/photos/question_everything/4320484939/
http://www.flickr.com/photos/krisgriffon/23263069/
29
http://www.flickr.com/photos/ali_pk/2349831732/30
31
All other illustrations are properties of:
To learn more about the wind turbine community, visit WindTurbines.Net.
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