Wind Power:
Wind Power is reasonable Renewable Energy Source that
can be used both hilly areas and smooth areas.
In 1891 Dane, Paula- Cour was the first person who generates the electricity by using wind turbine. It's very strange to hear he want to produce the Hydrogen gas so he electrolysis the
water by using the electric generated for his turbine.
Grandpa Knob in Vermont the world's largest wind power system used 1941
have the
capability to produce the 1250kW energy. They were designed to bear
115 mph airspeed but unfortunate they can’t afford the 25 miles per hour
speed of air in 1945 all the structure was destroyed.
Structure Types:
With respect to the wind turbine classified into two types.
1
Horizontal-axis wind turbines (HAWT)
2
Vertical axis (VAWT) ( commercially successful)
Calculate the power of wind
Pw = 1\2pAv3
Temperature Correction for Air Density
PV = nRT
Wind Turbine Generator
Wind turbine used the kinetic energy of the wind and rotate the shaft of the generator produced the electricity by means of blades.
Complete structure of wind turbine
Indirect
Grid Connection Systems
Variable-frequency output of the asynchronous
generator is rectified,
filtered and inverted to produce
acceptable 60-Hz power to the grid as shown in the figure
In this picture, the complete phenomena are shown. Wind move Fan
of turbine and Asynchronous Generator Produced electricity.A rectifier converts
AC to DC and an inverter converts again DC to 60 Hz Ac. At the end to remove
fluctuation and stable the supply we use the filter.
Wind Farms:
Now the point is how
many wind turbine would be installed at this place. If we install all the
wind turbines near each other they effect each other. For example,
the upwind turbines effect the amount of wind received which is
located downwind.
Due to upwind the
velocity of wind slow down which effect the speed of rotor
machine’s located downwind we can minimize the effect by installing the
turbines some distance.
The performance of
system decrease when all located too close.
The above figure shows
the effect of array efficiency with respect to the tower spacing. Here 4 types
of array mentioned which show a different number of turbine and area. For
example, in 2 × 2 shows array consist total 4 turbines have equally distance
each other, 8 × 8 show’s that 64 number of turbines installed in the square
area, 6 crosses 6 show 36 wind turbines in the equally spaced area and 4 × 4
has 16 turbines.
A number of the
array is inversely proportion to the efficiency of the wind turbine.
From the previous figure and theoretical study result
tells that the space between the tower in the row recommended is 3–5 rotor
diameters each one and the distance between the row of wind turbines
approximately 5–9 diameters.
Spacing b/w tower and rows
Tower
Height:
IMPACT OF TOWER HEIGHT
V/Vo = (H/Ho)^alpha
Condition Assessment
Techniques For Electrical Equipment
How check the Condition of Electrical Equipment's
PD monitoring
Features of PD measurement systems
Sensors (Coupling Devices)
Detectors
Sensors
Statistical Analysis
Condition Assessment
Techniques For Electrical Equipment
How check the Condition of Electrical Equipment's
PD monitoring
Features of PD measurement systems
Sensors (Coupling Devices)
Detectors
Sensors
Statistical Analysis
Transformer moisture measurement
Water
content of paper insulation
Tower
Height:
It is very important
to know that wind is not running smoothly and constant near the earth surface
so its very necessary to the high flow of wind to get maximum rotor
speed and try to reach required rpm.
But the question is
How to get maximum wind speed.
Height of tower
Shape of wings
A suitable
Generator etc …
IMPACT OF TOWER HEIGHT
The height
of the tower is very important. The velocity of wind is badly reshaped by
the variation of earth surface, a bit friction also effects when the wind moves
smooth surface as well as the clam sea. Few hundreds above the earth
surface obstacle disturb the wind like forest and building irregular
the flow of wind. We know that speed of wind is high and constant at height.
This equation show describes the relation of height and roughness of the
surface.
V/Vo = (H/Ho)^alpha
Velocity denoted V.
The height of tower
denoted by H.
Ho commonly used 10.
Vo wind speed at the
height of Ho.
Alpha
is fraction coefficient.
Z= roughness length.
The roughness of water surface is 0.0002 m which are lowest and
the heights are 1.6.
The speed of air very different with in the flat area
and hilly area. In the low wind speed area vertical blade shape of wind turbine
very preferable. There are on a lot of benefit of the vertical shape of wind
turbine.
· Vertical shape blade moves rotate at very low velocity.
· For the design of the small level wind turbine vertical shape of
blade used.
· They can move even when the direction of wind top to bottom.
· Vertical axis wind turbine works for all direction of wind doesn’t
matter what is the direction of the wind.
· Most important thing for the vertical wind turbine is
they do not concern of tower height.
Condition Assessment
Techniques For Electrical Equipment
How check the Condition of Electrical Equipment's
Condition assessment techniques are the very famous
method to look after the electrical equipment. These are used to identify the
significant changes which are caused by many problems and prevent the failure.
Due to these techniques, we check the tool as scheduled. There is a number of
the method but here I explain two techniques.
• PD
monitoring
•
Transformer moisture measurement
PD monitoring
The PD (partial discharge) is used many years for test
and investigates the insulation system design and check the level of quality of
new equipment. In the last 20 years the use of partial discharge increase
dramatically.Now a day these are used to diagnose the present condition of
electrical insulation in the using apparatus. It is used in like switchgear,
transformer, cables, windings of the stator in the generator and as well as in
the motors. PD has many qualities so that the use of partial discharge increase
day by day due to the sensors which are used in it is low cost, electronics as
well as the memory is effected its popularity. The use of ultra wide band
detection and the acutance in the measurement of the partial discharge in the
presence of noise are the methods that cause its (PD) popularity.
Partial discharge is produced due to electrical
breakdown of a gas (e.g. air) in the highly un specified electrical field.
Partial discharge is like a small electrical spark. The partial discharge will
degrade the level of organic material and sometimes cause the big fault and
stop working of electrical insulation if the void is present in the liquid or
solid of organic. The nature of partial discharge is destructive for over
previous 70 years in the oil-paper insulated high voltage cables as well as the
other high voltage equipment. The insulation of different instrument is made of
organic materials like oil, paper, polyester .polyethylene, rubbers,
polyester.We have to pay full attention to formed the insulation system of high
voltage cables, transformers, capacitors and switchgear that not include the
little amount of void in the region of electric high stress.
PD is also caused to destroy earlier the electrical
apparatus. At the result of the high-temperature operation, voids mix within
the epoxy mica insulation or oil-paper insulation due to this localized
electrical stress on insulation surface and discharge in the air. The
presence of Partial discharge cause the environmental mechanical and thermal
aging processes.
There is no doubt that the partial discharge
measurement method is devolved since 1930. There are many reasons to measure
the PD design test. It is simple to find the presence of PD for new insulation
system under the normal operation.
Quality Assurance: it is done to believe that partial
discharge is not the presence in the newly formed insulation system.
Diagnostic test: this is suing to identify the fault
due to thermal, cables the electrical and mechanical stress during the working
of insulation system in the transformer, switch cables the and aim and purpose
of these tests to find the PD level. If the amount of PD Level is too high then
it indicates of failure of system insulation permanently.
There is a number of a researcher who finds the method
of investigating the partial discharge during 1950 to 1980 like Bartnikas,
Kelen, Kreuger. These top researcher introduced a different method to show the
data and identify the PD. After a long time, these methods are used to measure
and detect the PD in laboratories and industries no a days.
the most famous researcher Bartnikas,
Kelen, Kreuger, Gulski and other prolific researcher take a step forward
and formed the advanced technology to measure the partial discharge.to the
point that off the line and on line. These online techniques are used in high
percentage transformers machines cables and switchgear that are working in the
world industrial countries.
Features of PD measurement systems
A famous researcher Bartnikes recently summarized the
theory of PD, calculation technology, and a brief overview of the partial
sensor.
Sensors (Coupling Devices)
electron move very fast form one side of gas-filled
void and pass another side when the partial discharge waves formed. The time of
these pluses is nanosecond and the electron moves at the speed of light. The e-
has charged and each discharge generates current waves I = DP/DT. A positive
charge also flows in opposite direction .the current generate a disturbance and
at conclusion current and voltage flow outside the PD site. At this time
the frequencies reach at several megahertz the Fourier transform of a current
shown.
PD pulse current can easily identify by any sensor
that can sensitive the high frequency. When we did an off line test then we use
a very high voltage capacitor which is connected to the terminal of high
voltage of the test object.
Partial discharge can also be detected by the
following
Electromagnetic
Radiation
Acoustic noiseVisible
and UV light
Electromagnetic radiation can be measured by RF
antennae.
Due to Discharge on insulation system electron and ion
formed a gas pressure that can be identified by the acoustically.
The final famous process is detected PD uses the fact
that the light that’s transparent the energize molecule and emit energy after
the discharge. When they pass through the spectrum a light is produced and a
naked eye can easily detect these rays of light on the surface f PD.
Detectors
partial discharge is detected by the voltage signal,
PD pulses current convert into the voltage signals because it is easy to detect
the voltage signal rather than current. The conversion takes place via a
resistor or R L C detection impedance is used.RLC identify the method of
resistance is very famous, the total number of ions and electrons and ions that
are bombarding the insulation surface is directly proportion the failure or decay
of organic insulation surface and if the rate of discharge is greater than the
decrease of insulation is faster.
Sensors
Many types of instruments are in the market to
calculate the signals which are from the Partial detector and sensors
combinations.
Analog oscilloscope was most famous and reliable tool
to calculate the PD showing signals it’s about last twenty years ago. The
pluses were calculated by the PC (vertical scale) versus the AC phase position.
The bandwidth of the oscilloscope at that time is very limited and the pulses
of PD appears on the screen of the oscilloscope for very minimum time so it was
very difficult to calculate the accurate magnitude of the pluses. The rate
of repetition of partial discharge pluses is not measured able, last
20 years are very important to the development of the instruments in the field
of PD deduction. Now a days all the instrument are digital infect the
instruments used before was totally analog. Due to the digital world, we can
easily enable to the separation of noise, continuous online PD monitors, PD
site Location and practical.
Statistical Analysis
This approach uses a skew, standard deviation and
kurtosis to identify the figure and location of positive and negative partial
pulses with respect to the AC phase angle. Every partial discharge mechanism
and each type of noise have unique set of mean phase angle, standard deviation,
skew, and kurtosis. (G.C.Stone, October 2005) This was the first
researched automates pattern to identify the method.PPA plot gives all raw data
.this is shown in the figure.
Z= roughness length.
The roughness of water surface is 0.0002 m which are lowest and
the heights are 1.6.
The speed of air very different with in the flat area
and hilly area. In the low wind speed area vertical blade shape of wind turbine
very preferable. There are on a lot of benefit of the vertical shape of wind
turbine.
· Vertical shape blade moves rotate at very low velocity.
· For the design of the small level wind turbine vertical shape of
blade used.
· They can move even when the direction of wind top to bottom.
· Vertical axis wind turbine works for all direction of wind doesn’t
matter what is the direction of the wind.
· Most important thing for the vertical wind turbine is
they do not concern of tower height.
Condition Assessment
Techniques For Electrical Equipment
How check the Condition of Electrical Equipment's
Condition assessment techniques are the very famous
method to look after the electrical equipment. These are used to identify the
significant changes which are caused by many problems and prevent the failure.
Due to these techniques, we check the tool as scheduled. There is a number of
the method but here I explain two techniques.
• PD
monitoring
•
Transformer moisture measurement
PD monitoring
The PD (partial discharge) is used many years for test
and investigates the insulation system design and check the level of quality of
new equipment. In the last 20 years the use of partial discharge increase
dramatically.Now a day these are used to diagnose the present condition of
electrical insulation in the using apparatus. It is used in like switchgear,
transformer, cables, windings of the stator in the generator and as well as in
the motors. PD has many qualities so that the use of partial discharge increase
day by day due to the sensors which are used in it is low cost, electronics as
well as the memory is effected its popularity. The use of ultra wide band
detection and the acutance in the measurement of the partial discharge in the
presence of noise are the methods that cause its (PD) popularity.
Partial discharge is produced due to electrical
breakdown of a gas (e.g. air) in the highly un specified electrical field.
Partial discharge is like a small electrical spark. The partial discharge will
degrade the level of organic material and sometimes cause the big fault and
stop working of electrical insulation if the void is present in the liquid or
solid of organic. The nature of partial discharge is destructive for over
previous 70 years in the oil-paper insulated high voltage cables as well as the
other high voltage equipment. The insulation of different instrument is made of
organic materials like oil, paper, polyester .polyethylene, rubbers,
polyester.We have to pay full attention to formed the insulation system of high
voltage cables, transformers, capacitors and switchgear that not include the
little amount of void in the region of electric high stress.
PD is also caused to destroy earlier the electrical
apparatus. At the result of the high-temperature operation, voids mix within
the epoxy mica insulation or oil-paper insulation due to this localized
electrical stress on insulation surface and discharge in the air. The
presence of Partial discharge cause the environmental mechanical and thermal
aging processes.
There is no doubt that the partial discharge
measurement method is devolved since 1930. There are many reasons to measure
the PD design test. It is simple to find the presence of PD for new insulation
system under the normal operation.
Quality Assurance: it is done to believe that partial
discharge is not the presence in the newly formed insulation system.
Diagnostic test: this is suing to identify the fault
due to thermal, cables the electrical and mechanical stress during the working
of insulation system in the transformer, switch cables the and aim and purpose
of these tests to find the PD level. If the amount of PD Level is too high then
it indicates of failure of system insulation permanently.
There is a number of a researcher who finds the method
of investigating the partial discharge during 1950 to 1980 like Bartnikas,
Kelen, Kreuger. These top researcher introduced a different method to show the
data and identify the PD. After a long time, these methods are used to measure
and detect the PD in laboratories and industries no a days.
the most famous researcher Bartnikas,
Kelen, Kreuger, Gulski and other prolific researcher take a step forward
and formed the advanced technology to measure the partial discharge.to the
point that off the line and on line. These online techniques are used in high
percentage transformers machines cables and switchgear that are working in the
world industrial countries.
Features of PD measurement systems
A famous researcher Bartnikes recently summarized the
theory of PD, calculation technology, and a brief overview of the partial
sensor.
Sensors (Coupling Devices)
electron move very fast form one side of gas-filled
void and pass another side when the partial discharge waves formed. The time of
these pluses is nanosecond and the electron moves at the speed of light. The e-
has charged and each discharge generates current waves I = DP/DT. A positive
charge also flows in opposite direction .the current generate a disturbance and
at conclusion current and voltage flow outside the PD site. At this time
the frequencies reach at several megahertz the Fourier transform of a current
shown.
PD pulse current can easily identify by any sensor
that can sensitive the high frequency. When we did an off line test then we use
a very high voltage capacitor which is connected to the terminal of high
voltage of the test object.
Partial discharge can also be detected by the
following
Electromagnetic
Radiation
Acoustic noiseVisible
and UV light
Electromagnetic radiation can be measured by RF
antennae.
Due to Discharge on insulation system electron and ion
formed a gas pressure that can be identified by the acoustically.
The final famous process is detected PD uses the fact
that the light that’s transparent the energize molecule and emit energy after
the discharge. When they pass through the spectrum a light is produced and a
naked eye can easily detect these rays of light on the surface f PD.
Detectors
partial discharge is detected by the voltage signal,
PD pulses current convert into the voltage signals because it is easy to detect
the voltage signal rather than current. The conversion takes place via a
resistor or R L C detection impedance is used.RLC identify the method of
resistance is very famous, the total number of ions and electrons and ions that
are bombarding the insulation surface is directly proportion the failure or decay
of organic insulation surface and if the rate of discharge is greater than the
decrease of insulation is faster.
Sensors
Many types of instruments are in the market to
calculate the signals which are from the Partial detector and sensors
combinations.
Analog oscilloscope was most famous and reliable tool
to calculate the PD showing signals it’s about last twenty years ago. The
pluses were calculated by the PC (vertical scale) versus the AC phase position.
The bandwidth of the oscilloscope at that time is very limited and the pulses
of PD appears on the screen of the oscilloscope for very minimum time so it was
very difficult to calculate the accurate magnitude of the pluses. The rate
of repetition of partial discharge pluses is not measured able, last
20 years are very important to the development of the instruments in the field
of PD deduction. Now a days all the instrument are digital infect the
instruments used before was totally analog. Due to the digital world, we can
easily enable to the separation of noise, continuous online PD monitors, PD
site Location and practical.
Statistical Analysis
This approach uses a skew, standard deviation and
kurtosis to identify the figure and location of positive and negative partial
pulses with respect to the AC phase angle. Every partial discharge mechanism
and each type of noise have unique set of mean phase angle, standard deviation,
skew, and kurtosis. (G.C.Stone, October 2005) This was the first
researched automates pattern to identify the method.PPA plot gives all raw data
.this is shown in the figure.
Pulse phase analysis plot of
the pulse magnitude versus AC phase position
with pulse count rate in
pulses per second represented as color.
Partial discharge ratio
changes as the pattern of PD. The pattern shape differs in the mean skew and
kurtosis with respect to the phase angle. Which is shown in the figure
Transformer moisture measurement
Water In the transformer cause to produced odd
substance, also decrease the insulation of break down. When a large amount of
water content of paper as a result bubbling produced and also increased the
chance of dielectric breakdown. There are three main source from which the
water comes in the transformer: residual moisture in the thick structure
element login from the atmosphere and cellulose, oil increase the speed of
decomposition the amount of moisture in the transformer is less than 1 %, but
the target value is 0.5 % when the new transformer is formed and ready to use.
Methods and instrumentation for moisture measurement
In the transformer industry, the term “moisture” is
used to differentiate the how much amount of water is dissolved in the
transformer oil or the amount the water absorbed in the paper.
Water
content of paper insulation
A new concept of measuring transformer moisture was
introduced which is based on the water in paper activity method. The different
aspect of water in paper activity used to measure the amount of moisture in the
both new one or old transformer insulation system. Another term “active water
content of the paper (WCP)” was also determined. This concept of WCP shows the
relation water in paper and oil in the insulation of transformer. The figure
shows the same parameter of water in paper activity to the active water content
of paper.
There is another way to determine the WCP of paper
insulation in a paper-oil insulation. System and equilibrium chart of moisture
is used.
In this show the difference between the water content
of oil (WCO) which is expressed in oil, the percentage moisture of paper and
the temperature.
Assessment of true oil relative saturation in the transformer
The HMP228 transmitter gives on line measurement of
the transformers moister and temperature.
Assessment of true oil relative saturation in the transformer
Thanks for Suggestion
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