CHAPTER (2)
COMPONENTS OF WIND TURBINE
2.1. Generator
The type of generator most used in wind turbines are the permanent magnet
synchronous generators. The term shaft usually refers to a component of circular cross
section that rotates and transmits power from a driving device, such as generator or
engine, through rotating of pulley with belts. Shafts can carry gears, pulleys to
transmit rotary motion and power via belts and chains.
The generator converts the mechanical (kinetic) energy of the rotor to
electrical energy. The energy in the wind turns two or three propeller-like blades
around a rotor. The rotor is connected to the main shaft, which spins a generator to
create electricity.
2.1.1. Advantages of Generator
(1)
For low speed direct drive wind turbine generator the permanent
magnet generator is more competitive because it can have higher
pole number of 60 or more poles compared to a conventional
wound rotor synchronous generator.
(2)
Simpler, more durable but does not allow control of excitation or
reactive power.
(3)
Permanent magnets are typically used in low power, low cost
synchronous generators.
2.1.2. Disadvantages of Generator
(1)
The frequency of the output voltage depends upon the speed of
rotation of the rotor.
(2)
no control of the rotor flux, they attain their peak efficiency only at
one pre-defined wind speed.
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Figure 2.1. Generator
Specifications:
Model:
JYCR9390H
Rated voltage:
230V AC
Rated speed:
1000 RPM to 5000RPM
Coils:
800 turns, 0.02 metre square,
Uniform magnetic field(B): 0.085 T
2.2. Windmill
A windmill is a structure that converts wind power into rotational energy using
vanes called sails or blades.
Wind turns the propeller-like blades of a turbine around a rotor, which spins a
generator with pulley belt, which creates electricity. The main components are the
foundation, the tower, the rotor and hub (including three blades). A structure that uses
the power of flowing air to produce electricity.
2.2.1. Advantages of windmill
(1)
Renewable & clean source of energy
(2)
Low operating costs
(3)
Efficient use of land space
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2.2.2 . Disadvantages of windmill
(1)
Intermittent
(2)
Noise and visual pollution
Figure 2.2.Windmill
2.3. DC Motor
The 12V DC motors are simple DC motors with shaft gears to achieve the best
performance characteristics. Center Shaft DC Geared Motors is so named because its
shaft runs through the center of the gearbox assembly. This 12V DC Motor has an
RPM of 6000.
It is a rotary motor which can convert the direct current into mechanical
energy or convert mechanical energy into DC power. They are also available in a
range of different voltages, the most common being 12 V and 24 V.
Figure 2.3. DC Motor
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Specifications:
Speed:
6000 RPM
Voltage:
12 Volts
Material:
Metal
2.4. AC-DC Power Supply
An AC-DC power supply, often known as an adapter, is a device that takes
electricity from a grid and converts it to a different current, frequency, and voltage.
AC-DC power supplies are required to give the correct amount of power to an
electrical component.
When selecting an AC-DC power supply, the primary consideration
is determining the system power requirements. This includes the AC input range and
the DC output specifications. The user should verify the AC input voltage range of the
power supply is compatible with their target markets and specified application.
Power supply voltage is the amount of electrical power that is being used to
operate a device or system. Voltage is measured in volts, and it is typically provided
by either alternating current (AC) or direct current (DC).
Figure 2.4.AC-DC Power Supply
Specifications:
Rate of change:
AC 220V to DC24V
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Ampere:
10A
Frequency:
50/60 Hz (47 to 63 Hz range)
2.5. DC Speed Controller
The DC Motor Speed Controller allows controlling direction of a DC motor
using a Pulse-Width-Modulated (PWM) DC voltage with a Duty Cycle fully
adjustable from 10% ~ 100%. The motor speed controller can provide a continuous
current of 10A to your DC motor or other DC load.
It is used to influence the rotational speed of motors and machinery. This has
a direct effect on the operation of the machine and is crucial for the quality and the
outcome of the work. A DC motor's speed is directly proportional to the input voltage.
The higher the input voltage, the faster the output speed. The lower the input voltage,
the slower the output speed.
Figure 2.5. DC Speed Controller
Specifications:
The maximum output power: 1000W
The maximum continuous output current: 10A
The overload and short circuit protecting current is 15A
Frequency: 16KHz
Duty Cycle adjustable: 10% ~ 100%(600 RPM to 6000RPM for motor)
The operation environment temperature: -20°C ~ 40°C
The 20A fuse with reverse connection of power supply and control voltage overvoltage protection function
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Size: 64 x 59 x 28mm
2.6. Pulley Wheels and Pulley Belts
Pulley wheels are used to transfer the rotational energy from the rim to one or
more generator mechanisms. The pulley wheel that controls the wind mill must be
built larger than the pulley wheel that drives the generator within the pulley belts.
For every turn of the windmill’s pulley wheel, the generator’s pulley wheel
will turn 3 times. The higher generator speed, the more electricity it generates. The
primary purpose is to have controllability of the kinetic energy stored in the rotating
drive train. This is carried out by controlling the inertia of the wind turbine rotor. The
spinning of the wheels functions with belts as the blades of a windmill.
Rotational movements are transferred between the pulleys by means of
the belts. Thus, the gear arrangement is in the form of a belt drive.
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Figure 2.6. Pulley Wheels and Belts
Figure 2.6.1. Structure of Pulley Wheels and Belts
2.7. Bridge Rectifier (used 6 diodes)
The Bridge Rectifier contains 6 diodes. Three diodes already connected in
series are connected in parallel again. The diodes used are pn-type diodes.
The electricity coming out of the generator is three phase AC. This electricity
enter three pins_terminals of the rectifier. A rectifier converts three phase AC to
single phase DC such as plus and minus terminals.
Various varieties of diodes share the same basic structure of a p-type material
region meeting an n-type material area. The different types are optimized to produce
distinct properties. These properties can be employed in a number of ways in many
electronic circuit designs.
The factors to consider while choosing a diode are given below:
1. Reverse Voltage: Choose a value that is more than the highest possible reverse
voltage seen across the device (when the diode is turned off).
2. Forward Current: Set to be greater than the maximum potential current
perceived flowing through the device (when the diode is turned on).
3. Forward Voltage: Determine if the modest voltage drop in the forward
direction must be at or below a specific value (when the diode is turned on).
4. Peak Inverse Voltage: The rectifier diodes must be able to tolerate the peak
inverse voltage applied across them. When a capacitor smooths the output, the
voltage value is the peak of the input waveform, which is √2 times the RMS
voltage
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Figure 2.7. Bridge Rectifier (used 6 diodes)
Specifications:
Voltage Rating:
Over 120V AC
Current Rating:
50A
Junction temperature:
-40 to 150’C
Storage temperature:
-40 to 150’C
2.8. DC Step-Down Device
A step-down device is an electrical device that is designed to reduce the
voltage. It works by having more turns in its primary coil than in its secondary coil,
which results in a lower voltage output in the secondary coil compared to the input
voltage in the primary coil. Step-down device are commonly used in electrical devices
that require a lower voltage than the mains voltage, such as electronic devices,
appliances.
For example, the power supply of many electronic devices, such as laptops,
smartphones, and televisions, use step-down device to convert the high voltage DC
power from the mains supply into a lower voltage DC power that can be used by the
device. As the lighting loads to be used are 12V, the single phase DC voltages from
coming out of the rectifier are reduced to 12V by the step-down device depending on
the voltages of windmill power and generator.
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Figure 2.8. DC Step-Down Device
Specifications:
High voltages of rating:
Over 12V DC
Reduced voltages rating:
12V
Load:
1650W
Output current:
2A
Winding:
Copper
2.9. Ridged Loop Lights (LED)
This product is a pair of angel eyes headlights that are made of white silica
gel. They are super bright and have a cob ring light. They are designed to be used
with a DC power supply. Ridged loop lamps are a very longlife festoon designed for
the very best lighting quality in high end installations.
The electric voltages from coming out the step-down transformer energize the
12V 1.5Watt, ridged loop light.
2.9.1 Advantages of ridged loop lights (LED)
(1)
Low Voltage Operation.
(2)
No Heat or UV Emissions.
(3)
Long Lifespan.
(4)
Improved Environmental Performance.
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2.9.2. Disadvantages of ridged loop lights (LED)
(1)
They emit more blue light than incandescent bulbs.
(2)
LED lamp systems increase the blue hazard
Figure 2.9. Ridged Loop Lights (LED)
Specifications:
Rated Voltage:
12V
Wattage:
1.5W
Output:
40 Lumens
Diameter:
10mm