The document provides an overview of wind turbine operation and maintenance. It discusses the components of a wind turbine including the rotor blades, gearbox, generator, control systems, and tower. The key components work together to convert the kinetic energy of wind into electrical energy. Sensors monitor turbine operations and controls adjust the blades to optimize power output while ensuring safety during high winds or other events. Regular maintenance is needed to inspect components like the gearbox and replace parts like slip rings.

1. Operation and Maintenance of
Wind Turbines
Speakers
Abdullah Aftab Asjad Ali
(O&M Engr SGRE) (O&M Engr SGRE)

2. Introduction
• Wind turbines - a successful technology for
clean and safe production of electricity.
• Fastest growing renewable energy source.
• Globally recognized as environment friendly
and sustainable.
• Emerging as a economically competitive
source of energy.
• Wind energy will never run out, and is very
helpful in mitigating CO2 production.

3. Wind as a source of energy
• Wind is air in motion.
• It has a mass.
• A mass in motion has a
momentum
• Momentum is a form of
energy that can be
harvested.
• Wind energy relies on
sun. Wind is created by
uneven heating of the
earth’s surface.

4. Global creation of Winds
• Uneven heating of the
earth's surface. When
sun hits one part of the
earth more directly, it
warms that part up. The
warm air rises and
cooler air rushes in,
creating wind.

5. Kinetic Energy in the Wind
• Kinetic Energy = Work = ½mV^2
• Where:
• M= mass of moving object
• V = velocity of moving object
What is the mass of moving air?
density (ρ) x volume (Area x distance) = ρ x A x d
= (kg/m3 ) (m2 ) (m) = kg

6. Power in the Wind
• Power = Work / time
= Kinetic Energy / time = ½mV2 / t
= ½(ρAd)V2 /t
= ½ρAV2 (d/t) = ½ρAV3 d/t = V
Power in the Wind = ½ρAV3

7. • Power in the Wind =
½ρAV3
• Swept Area – A = πR2
(m2 ) Area of the circle
swept by the rotor.
• ρ = air density – in
Pakistan its about
1.225-kg/m3.

8. The Betz Limit
• A maximum of 59.26% of the available wind
power can be converted to mechanical power
at ideal conditions

9. Wind Energy Conversion

10. Power Conversion

11. Vertical Axis Wind Turbines

12. Horizontal Axis Wind Turbines
• Commercially used
• More Stable
• More Reliable
• Produce greater Energy
compared to vertical
axis

13. Mechanical-Electrical Single Line
Diagram

14. Components of Wind Turbine

15. Wind Turbine Components
• Rotor, or blades, which convert the wind's
energy into rotational shaft energy.
• Nacelle (enclosure) containing a drive train,
usually including a gearbox (Some turbines
operate without a gearbox) and a generator.
Tower, to support the rotor and drive train.
• Electronic equipment such as controls,
electrical cables, ground support equipment,
and interconnection equipment.

16. Wind Turbine Components
Rotor
• Comprises of all turning
parts of the unit outside
the nacelle
• Rotor Blade
• The hub
• Blade pitch mechanism

17. Rotor Blades
• Blades
Blades sweep around air
and further rotate shaft
which in turn rotates
generator rotor.

18. Real Time Blade Pitched at 87 degrees

19. How Does Turbine Rotates?

20. Turbine Power

21. Power Control of Turbine
Power Control through Aerodynamic
(Angle of attack, Pitch angle, Lift & Drag)
• Stall control
• Pitch control

22. Power Control of Turbine
Pitch Control
• Pitch controls adjust the
blades in wind turbines by
rotating them so that they use
the right fraction of the
available wind energy to get
the most power output, all the
while ensuring the turbine
does not exceed its maximum
rotational speed. This
maintains the turbine’s safety
in the event of high winds, loss
of electrical load, or other
catastrophic events.

23. Stall Control
• Blades are fixed at a
specific pitch angle and
start to stall in case of
high wind

24. ROTOR BLADE-MATERIAL
Materials
Al, Titanium, Steel, Fiber reinforced composite material
Fiber reinforced composite
Material blades currently used in almost all WT structure
Types:
Glass fiber
Carbon fiber
Organic aramid fiber (Kevlar)
Mostly used is glass fiber -Strength properties are
extraordinarily high

25. Carbon fibers
• Has longest tearing strength
• High modules of elasticity
• The stiffness of carbon fiber
components is comparable to that of
steel
• Fatigue properties are good

26. Number of Blades
• Most common design is the three-bladed turbine. The
most important reason is the stability of the turbine. A
rotor with an odd number of rotor blades (and at least
three blades) can be considered to be similar to a disc
when calculating the dynamic properties of the
machine.
• A rotor with an even number of blades will give
stability problems for a machine with a stiff structure.
The reason is that at the very moment when the
uppermost blade bends backwards, because it gets the
maximum power from the wind, the lowermost blade
passes into the wind shade in front of the tower.

27. Hub Of Turbines
• All major parts fixed
relative to the main
shaft in which blade
pitch can be varied no
other blade motion is
allowed
• The main body of the
rigid hub casting or
weldment to which the
blades are attached.

28. Inner Hub of Wind Turbines

29. Inner Hub of wind turbines

30. Drive Train
Complete wind turbine drive train consist of
all the rotating components
• 1. Main shaft
• 2. Coupling
• 3. Gearbox
• 4. Brake
• 5. Generator

31. Shaft
• Cylindrical element designed to rotate
• Transmit torque
• Attached to the gear pulley and couplings
• Wind turbine shafts are especially found in
gearboxes, generators and linkages.

32. MAIN SHAFT / LOW SPEED SHAFT /
ROTOR SHAFT
• Transfer torque from
the rotor to the rest of
the drive train and
transfer of all other
loads to the nacelle
structure
• Supports the weight of
the rotor
• Made of steel

33. Low Speed Shaft

34. High Shaft
• Connecting shaft of the
gearbox outlet to the
electric generator
rotates with nominal
speed of 1500 RPM
• Fitted with flexible
coupling at each end to
cater for small
misalignment between
generator and gearbox

35. High Speed Shaft

36. PLANETARY GEARBOX
• Input and output shafts
are co-axial
• There are multiple
pairs of gear teeth
meshing at anytime
• Loads on each gear
reduced

37. Planetary Gearbox
• Planet carrier rotates with the same carrier arm
rotational speed of the rotor blades
• Three planet wheel turn around inner
circumference of the ring wheel
• Increase the speed of the sun wheel
Advantages:
• Always three gear wheels supporting each other
and that all gear wheels are engaged at the time
• in principle it only needs to about a 1/3 of the
size

38. Doubly fed induction generator

39. Doubly FED Induction generator-Super
synchronous Operation

40. Synchronizing with frequency

41. Doubly fed induction generator
• The configuration known as DFIG (Double fed induction
generator) correspond to the WRIG (Wound rotor induction
generator) with partial scale frequency converter
• The partial scale frequency converter performs the reactive
power compensation and ensures smoother grid
connection
• The generator has a wider range of speed control, e.g., (-
40% to +30%) around the synchronous speed (wider than
OptiSlip)
• The use of slip rings and protection in case of grid faults is
a major drawback
• Variable speed operation is obtained by injecting a
controllable voltage into the rotor at the desired frequency

42. Doubly fed I.G
• Advantages and disadvantages
Advantages
• Reduced-capacity converter (cost, efficiency)
• Decoupled control of active/reactive power
• Smooth grid connection
• Disadvantages
• Regular maintenance of slip ring and gearbox
• Limited fault ride-through capability

43. Synchronous Generator and Carbon
Brushes
Slip Ring and Carbon Brushes

44. Control and Protection systems
• Increasing use of advanced electronics for
• Generator, converter and power control
• Pitch system
• Start, stop and sequencing
• Surveillance

45. Why do we need a control!
• The primary energy source is non linear and
unpredictable. Increase in wind speed develops
an enormous power in rotor – To be optimized
• To transfer the electrical power to the grid at an
imposed level, for wide range of wind velocities.
• To meet power quality requirements
• To detect the abnormal conditions and
preventing the wind turbine from possible
dangerous situations
• Achieve desired function and Safe Operation

46. Control system
• Control system consists of
• Various sensors, Transducers and Limit
switches (input)
• PLC (Process)
• Circuit breakers, Converters, contactors and
relays (output)
• Set point list

47. Important functions of Control system
• Alignment to the wind by Yawing
• Start-up and shutdown procedure
• Connection of the electrical load
• Rotor speed Control
• Power limitation
• Cable twist limits
• Temperature control

48. General Sequence

49. PROTECTION SYSTEM
• Over-speed
• Generator overload or fault
• Excessive vibration
• Abnormal cable Twist

50. NACELLE
• The nacelle cover is the wind turbine housing
Protects turbine components from weather
• Reduces emitted mechanical sound Material
• G-FRC glass-fiber reinforced composite
materials
• On larger Machines it has a hole that it can be
entered personal for inspector (or) maintains
the internal components.

51. Inside of a Nacelle

52. Inside of a nacelle

53. Main Frame
• Transfer the rotor loading to the yaw bearing
and to provide mountings for the gearbox and
generator
• Either welded beam or casted

54. Yaw Control
• Rotate the nacelle with respect to the tower
on its slew bearing
• Keep the turbine facing in the wind
• Unwind the power and other cables – Wind
Vane on nacelle tells controller which way to
point rotor into the wind – Yaw drive turns
gears to point rotor into wind

55. Yaw Drive
• Rotate the nacelle with
respect to the tower on
its slew bearing
• Keep the turbine facing
in the wind unwind the
power and other cables

56. Yaw clamps and Yaw Drive
• Yaw clamps acts as
break and keep the
nacelle at fixed
position.

57. Converter Cabinet
• A power electronic converter
enables efficient conversion of
the variable frequency output
of an induction generator,
driven by a variable speed
wind turbine, to a fixed
frequency appropriate for the
grid or a load..
• All the power is transmitted to
the grid through the converter.
The converter tracks the
frequency and phases of grid
voltage to keep the output
current and frequency of
turbines in consistent with
those of the grid

58. Converter Cabinet

59. Tower
• Made from tubular steel,
the tower supports the
structure of the turbine.
Towers usually come in
three sections and are
assembled on-site.
Because wind speed
increases with height,
taller towers enable
turbines to capture more
energy and generate
more electricity.

60. Towers
• Towers are stacked
upon one another
• Mostly there are more
than one parts of a
tower fastened to one
another with huge bolts

61. Operations and Maintenance of
Turbines
Maintenance of wind turbines involve
• Tensioning of blades bolts
• Torquing of all the towers bolts, main frame,
main shaft disc, generator feet etc.
• Greasing of Generator, yaw teeth's.
• Cleaning of Fiber and Platforms

62. Tensioning of blades
• During Tensioning of Blades a
pressure of 1000 bar using a
Tensioner pump is given and
bolts are tightened that are
loose before any catastrophe
happens.
• When pressure is applied on
the bolt, the tensioner pulls
the bolt upwards and using
ratchet bolts are tightened.
• Precautions are important
when dealing with such high
pressure, a little mistake can
put your or others life in
jeopardy.

63. Torquing of bolts
• Using different Keys at different
pressures, the bolts in the tower
and inside the nacelle are
tightened
• For the first tower, the pressure is
425 bar and 400 bar onwards for
remaining, the yaw tower is
tightened at 374 bars.
• Inside the nacelle, the bolts of
main frame are tightened at 500
bars and there are different
pressures for other bolts.
• Different RT’s mainly RT 5, RT3
and RT2 are used with different
key sizes mainly 36, 27, 46
depending upon the size of bolt.

64. Greasing of blades, yaw teeth and
Generator and cleaning
• Greasing of yaw teeth,
Blades and generator is
done after 3 months and
6 months. This is known
as 3M/6M maintenance.
• Cleaning of wind turbine
is very important as the
dirt particles can lead to a
lot of warnings and
alarming situations on
turbine.

65. Operations in Wind Turbine
There are number of alarms that can occur on
turbine, and they are the major reason for
availability loss of any wind turbine. So, it is very
important to keep the turbine on going and
available for power production. Some alarms are
removed using SCADA, but some are removed
by fixing the fault or any intricacy on turbine.

66. SCADA
Real time instantaneous data
of wind turbines is monitored
an analyzed. Any abnormality
is observed and removed.
Operators monitor wind
turbine production 24/7.

67. Total Wind Capacity of Pakistan
• Currently, 1836 MW of power is being
produced from wind in Pakistan while Pakistan
has more than 132,000 MW capacity on wind
including both off shore and on shore.
• The recent wind Plants that are set up in
Pakistan has each turbine with capacity of 2.1
MW power production.
• Wind is the second most biggest source of
clean energy in the World.

68. Wind Map of Pakistan

69. THANKS For Your Time