Showing posts with label Hydro Energy. Show all posts
Showing posts with label Hydro Energy. Show all posts

Monday, 24 September 2018

Can 100% Renewable Energy Power The World


Every year world use 35 billion barrels of oil this massive scale of fossil fuels dependents pollutes the earth and it were not last forever. The scientist researcher that we consumed 40 % oil according to the present estimate. This rete will run out oil and gas 50 years and coal in an about a century.
On the other side we have abundant solar, water and wind these are renewable resources. So the point is how we can change the world from fossil fuels to renewable sources.
This question rises since a century but it’s hard to answer?

Yet renewable energy provide only 13% of our needs that’s requires 100% that’s inexpensive and accessible. This represent a huge challenge we ignore the politics involve and focus of science and engineering we can better understand the problem by understanding how use energy. The global energy use is a dive race and complex system. The different element require their own solution but now we focus on these to familiar used in daily life.
The electricity and liquid fuel. Electricity powers a lot of things in industry as well as home. Liquid fuels play a crucial role in the transportation.
Let consider the electrical portion first the great news is our electrical advance technology can get energy from every form of renewable source.

 The Sun is the fundamental source of solar energy and continuously accelerates 173 Quadrillion Watts of solar energy at the earth. Its approximate 10000 time more than our need. It is estimated that the surface expands almost 7000 km will be needed to power humanity and our present usage level so, why we not builds that because there are other difficulties like efficiency and transportation.
Firstly the desert are the best places for solar energy but they are located for away from our populated areas where the electricity demand is very high. We transmit the energy by cables through pole that is too expensive and energy loss.

Today the transmitted lines loss the energy 6 to 8% and longer power line dissipate more energy the only super conductor can reduce this loss but they require cool surface not a heated places.
The other solution is we convert the all renewable energy into easily transportable form. We can stores the energy in lithium dry batteries which is low weight and efficient.

There are other sources like hydroelectric, geoelectric and wind energy but they depends upon the location and availability.  


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Friday, 18 May 2018

Is the WIRELESS Electricity is the Future ? See How the Wireless Charger Works on Principle




Inductive Charger / Wireless Charger

Michal Faradays discoveries the underlying principles of electromagnetic induction he discover that
in the presence of alternating electromagnetic field emf produces along the conductor.









  By the late 1894


Tesla used that idea and demonstrated the phenomena resonant electro coupling by lighting the incandescent lamp by tuning the current resonant frequency of the coil the two coil are join for higher
efficiency power transfer.




The discovery let to the modern electric motor and other  measurable invention however the inductive charging the science proof easier than implementation at the start won’t many electronic that greatly benefits such technology for the days of Tesla and due to limitation of circuit board design and size it was up to until 1999 and 2000 technology development for consumer level and we started seeing wireless electric tooth brushes and 2008 wireless charging mobile phone .

Inductive charger consist of few pads
Alternating current for watt and electronic oscillator circuit and transmission coil. The Transmission  base in thing like number of turn on wire diameter of coil the distance from the coil and other properties such a current.
coil is the tightly wound the copper element as a alternating current passes true to produce the magnetic flux that magnetic flux density



Under receiver end the processes is basically same expect opposite  On the receiver side Same type is embedded in the charging circuit the alternating magnetic field is picked up by the receiving coil the current is induced the AC power is passing through power rectifier stabilizer to convert the DC power phone  can use to charge the battery both the transmitter and receiver have electrical resonant frequency designed to be the same for low displacement distances such as a mobile  phone on charging  pad it is actually less efficient to  operate circuit resonant  frequency to generation









However for large displacement such a car park on charging pad operating at resonant frequency causes inductive coupling to counter act some displacement related transmission losses there are many other factor that fact on the performance there is no standard design on phone at yet charging pad needs way to detect to the type of devices that’s it is charging and Have of multiple coil arrangement.


A team of Engineers is working on advancement of charger that can charge up to 4 devices at a time and it will be completely safe.

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Monday, 2 April 2018

Near field Radio Frequency Identification Technologies


This category depends upon the faraday’s principle of magnetic induction for the process of the coupling between the single reader and the series of tag. As a reader is able to pass a large amount of alternating current from the cross section of the reading coil. This also results varying the alternating magnetic field relatively in its cross section locality. When a tag is placed who's cross sectional are is small relatively  and also the smaller coil then the alternating voltage is induced  across it terminal. When this induced voltage is processed through rectification process and is connected to a capacitor bank then a large reservoir of the charge is accumulated through it. which is used to provide the power to the series of tag chip.

Series of tags which use near field coupling transfer the data to the previous  reader with the help of  using load modulation method. As all the current which is drawn through the series of tag coil gradually will provides the increment in poor  magnetic field. This poor magnetic field opposes the main advanced reader’s series of field. The testing coil can predicts this at a small incremental of current which is passing from it. This passing current is directly proportional to the combined. The principle used for this purpose is same as used for that of power transformers.

 As in the transformer effect the primary and secondary coils are connected magnetically not electrically. When the magnetic field through the primary winding increase through specific level then the secondary winding acquires this magnetic field. And it behaves the same role as the tag for the reader. The reader monitors this signal and recovers it. This recovering is done by changing the value of the current. Different types of modulation encodings are established which are based at the complete number series of registers and of ID bits.
Near-field coupling is completely a best technique to implementing practically a number of passive radio frequency identification system. With its advantages the narrow field also has some disadvantages and restrictions. The periodic range used  for  this purpose is approximately c/2Ï€f. In this periodic approximation c shows a constant value which is also called  speed of light. Where f represents  the frequency. So when the frequency of increases automatically then the measuring distance decreases upon which the field coupling is depending.
 Moreover a specific limitation is required for the energy which is existing as the induction. This induction is the function of distance. It is connected with the reader coil. In this case the dropping factor for the magnetic field is near 1/r3. In this factor the r is representing the value of distance between or the separation of the tag and the reader. It is along the direction of center line. This center line is mutually perpendicular to plane of coil. In this case more ID bits are also required.



By the way the near field radio frequency communication system also has some restrictions and limitations physically. For this purpose the range used is near about c/2Ï€f and it has magnetic effect.
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Sunday, 12 March 2017

FIR FILTER

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Thursday, 9 March 2017

PCB Designing

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Thursday, 16 February 2017

Some assumption of key gases in the transformer (DGA)

These are some assumption of key gases in the transformer.

Assumption #1:

An arc is produced in the working transformer caused by the Acetylene, So it is easy to diagnose the condition of arcing solely by the help of the acetylene.

Analysis:

The practitioner does not investigate and understand the nature of the arc by the help of this assumption. The question that is it a not dangerous condition of sparking partial discharge in the transferor oil from the grounded part?  There is not a first class of very high dangerous to discharge energy? The high temperature in the transformer produced acetylene and the acetylene make a fault in the transformer oil or rather then produced an electrical arc? It is dam possible that it is the result of mixing or leakage the oil in transformer between the main tank and the LTC tank? All these question are not answered at easily but take the ratios of acetylene to the other gasses into the account. The in accurate result of findings does not mean there is a less dangerous or permission to a high problem to worsen. Due to lake of correct result the situation become over treated like de energizing, draining, incepting the tank and found no prove the reason is partial discharge cannot be seen with bear human eye. 
Assumption # 2:
Transformer show alert as overheated cellulose because carbon monoxide is present in it So it is very easy and reliable to investigate the cellulose problems solely by looking the carbon mono oxide.
Analysis:
  
According to the IEC data of incepted case in service .During the formation of carbon monoxide using the identifier paper involvement in a problem. A inaccurate result will be provided in about 65% of case.

The amount of carbon mono oxide increase it does not mean that any fault involving paper. The fault predicting depend very strongly on the presence of carbon di oxide amount. But actually the increasing amount of carbonmono oxide are directly related to the oxidation of oil it is seeing a large number cases and at the end the result shown increases the heating effect. Now a day all the transformer is equipped with the air preservation system because a small amount of oxygen is always present in the transformer due to leaks in these systems.
Carbon mono oxide by itself not a trustable and safe indicator. It damage the localized insulation paper and these are the following reason behind,
·         The amount is commonly reduced by dilution in a large amount of oil.
·         The level is affected by oil temperature absorption and desorption by paper insulation caused by load.
·         Its ability to move out in the transformer depend upon the oil expansion system type  and the bounding of transformer how tightly is sealed.

Assumption # 3

Hydrogen gas  predict the faults and the partial discharge so it is very sinificient to measure the hydrogen.

Analyze:


Hydrogen is also a key gas and it is present in all problems. So it not to use as a diagnostic gas but it is a predictor. It should be gather with other gases to find the problems with them as a ratio based analysis.in the key gas method three other gases are also include. The methane gas gives batter response when it is combine with hydrogen as a as diagnose and It happened when gases ratios are used. The reason behind is hydrogen gas soluble minimum amount oil. It has also high diffusion ability. (Serveron Corporation)






Conclusion:
In summary the indicator used in the transformer to predict the potential problems in the transformer should not be limited its totally depends upon the concentrations of the dissolved key gases. Identified the problems by trending the gas dissolved levels because we take some step before the tragic failure of the transformer. If the results of key gases concentration is different than we should take another sample to check the correctness of the result. If it clear that the concentration level is increase then use the well knows method to find the problems in the transformer and try to solve the problem.
Dissolved Gas Analysis organization work very hard for batter diagnostic instruments and their progress in this field. DGA expert always gets latest news and takes benefit. Mostly instruments are very good to perform than others. It is very reliable and comfortable to analyses the condition of the transformer. It is very strong program to analyses in laboratory as well as online dissolved gas analysis approaches.
We also analyze that the gasses generated in the transformer occupy with the beta fluid. They have same rule to analyze these gases and the conventional transformer oil and from the test its shows that the amount of gases that produced in the beta fluid due to different types of faults are same for those gases that is produced in the transformer convention oil. Another similarities is solubilizes of gases in the transformer is approximately 10 percent and the same amount of soluble in the beta fluid. 
These graphs dhow the percentage faults at different level.


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Wednesday, 15 February 2017

Evaluation of Possible Faults by the Rogers and Doernenburg Ratios in the Transformer Oil.

Evaluation of Possible Faults by the Rogers and Doernenburg Ratios in the Transformer Oil.
it is righty said that the concentration gas ratio is more trustable way from which we can easily understand and predict the fault inside the transformer. Rogers and Doernenburg were developed these ratios in European.
The following ratios are used:
Ratio 1 (R1): CH4/H2
Ratio 2 (R2) C2H2/C2H4
Ratio 3 (R3) C2H2/CH4
Ratio 4 (R4) C2H6/C2H2
Ratio 5 (R5) C2H4/C2H6
Doernenburg Ratio Method, Step 1
A sample of gas is collect from the head space which was above the level of oil in the transformer.
Doernenburg Ratio Method, Step 2
Be sure your method of calculation is true. One of the concentration of gases like hydrogen, methane, C2H2 and C2H4 must be as well as two times of the L1 values (below) and concentration of other three gases increased to the value of limit L1and it show that the transformer is faulty. As minimum as concentration of a single one gas must be increase the L1 values that’s given below.

Dissolved Gases
L1 Value ppm
Hydrogen
100
Methane
120
Carbon Monooxide
350
Acetylene
35
Ethylene
50
Ethane`
65

Hydrogen 100 Methane 120 Carbon Monoxide 350 Acetylene 35 Ethylene 50 Ethane 65
Doernenburg Ratio Method, Step 3
Suppose that the analysis ratio is true for this transformer and also check the ratio in order of R1, R2, R3, R4.
Doernenburg Ratio Method, Step 4
Now look all the calculating ratios which is measured for a particular task exist in the given table. If the ratios is present in the table than our suggested diagnosis is true.

Doernenburg Ratio for Gases key
Indicated fault
Diagnoses
Ratio 1
Ratio 2
Ratio 3
Ratio 4
Thermal
Decomposation
.1-1.0
.75- 1
.1 - .3
.2 - .4
Corona
.01-.1
Not significient
.1- .3
.2 - .4
Arcing
.1 – 1
.75- 1`
.1- .3
.2-.4

Doernenburg ratios, Rogers ratios, and Duval’s Triangle Mode are some commonly used techniques include application.
Doernenberg ratios and Rogers ratios are recognized in the ANSI/IEEE
C57.104. CH4/
H2, C2H2/C2H4, C2H2/CH4, C2H6/C2H2 and C2H4/C2H6. (Hamrick, 2009-2010)
Gases are also dissolved in mineral oils with different rates .We can easily find the fault by absorbs the ranges of ratios. The range of different gases is given in the table.
Rogers Ratios Method:
Rogers Ratio method have same process to measure the ratios as well as the process of Doernenburg method but three is only difference is that only three ratios are used in it. 

 



Duval’s Triangle Model is known in IEC Guidelines. The Duval Triangle Model (IEC 60599) is published in 1989 by increment in 2002.Calculate the total amount of three key gas ethylene (C2H4), ethylene (C2H4), ethylene (C2H4) and then divide total of all gases to calculate the percentage of each one gas and find the problems in transformer using the key gasses After that plot a triangle from these values which was absorbed.
In the triangle  the temperature  effect with ratio are shown like thermal fault <  300 ºC, thermal fault 300-700 ºC, thermal fault> 700 ºC; low-energy discharge; high
energy discharge; and partial discharge.
Sometimes the ratio to key gases CO2 and CO act as a alarm in the decomposition of cellulose .It is often seen that the ratio of formation of key gas CO2 is usually 7 to 20 time greater than CO. If the ratio of both these gases is greater than 7 then it consider to be at normal level and if the ratio of carbon di oxide and carbon mono oxide is 5or less than 5 then it is the indication of optional problem. Sometimes additional furan test is required to perform when if the degradation of cellulose is problem carbon mono oxide, hydrogen, methane and C2H6 are also increase. The transformer consider faulty for more inception if the ratio of carbon mono oxide and carbon di oxide ratio is 3 or less than 3 with the increased the furans. Due to overheating, chemicals and in the addition of Carbon di oxide, carbon mono oxide the cellulose decompose and released in to the oil. The mixture which formed during this process is known as Furans or furanic compound.  
In the fault free Transformer the amount of furan is negligible in the oil (<100ppb). The amount of furans increase when the quantity of cellulose decrease. When the furan levels between 500 to 1000 ppb then it shows the cellulose growing older and showing the effects of increasing age. And when the furan levels greater than 1500 ppb then it show the potential harm of insulation.

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Monday, 13 February 2017

Different method to Analyze to Combustible Gases in DGA Transformer oil Testing

Different method to Analyze to Combustible Gases in DGA Transformer oil Testing

There are a number of method to predict the Dissolved Gas Analysis in the transformer which is filled with beta fluid. The following processor that are recommended by dielectric system

Evaluation of Transformer Condition Using Individual and TDCG Concentrations:

These methods are suggest by IEEE Standard C57.104.when we have not the previous Dissolved gas history then a four level processes is define to understand the risk of inside the transformer. In the given table the concentration of gases are defined.

Condition 1

Total dissolved combustion gas show the transformer operate satisfactory manner if the TDCG below the level. If we find the concentration of gas increase for the given value then we should investigate the reason and try to find the fault.

Condition 2

In this stage it show that the combustible gas concentration is greater than the normal TDCG indicate and we should investigate the any single one gas increasing concentration for the specified level.

Condition 3

In this stage the TDCG indicate the level of decomposition is high. Any one gas which one increase its concentration level we should explore immediately if we doing this we easily recognized the fault present in the transformer. 

Condition 4

At this last condition these values indicate the proper transformer condition .TDCG indicate that the decomposition of beta fluid and the cellulose is uncontrolled. If we star doing work with transformer then the maximum chance that the transformer stop doing work due to out of order.



At this last condition these values indicate the proper transformer condition .TDCG indicate that the decomposition of beta fluid and the cellulose is uncontrolled. If we star doing work with transformer then the maximum chance that the transformer stop doing work due to out of order.


We can easily find the present condition of particular transformer by finding highest for a single one gas. A year old transformer as well as contain the level of gases that would be below the condition 1 and not enough acetylene is present in the transformer to detect. 

Evaluation of Possible Faults by the Key Gas Method

There are four type of faults which is presented in the key gases and cause to produce the problems. Key Gas Method not as precise but it is use widely in the investigation of faults in the transformer. Key Gas method is use to in beta fluid for the investigation of transformer conventional oil.

Fault Type: Thermal decomposition of Beta Fluid

Principal Gas: Ethylene Characteristics:
Ethylene and methane are produced from decomposition and along with small amount of hydrogen and ethane.

Fault Type: Thermal decomposition of Cellulose

Principal Gas: Carbon Monoxide Characteristics:
Carbon mono oxide and carbon di oxide is produced for the decomposition of cellulose. Hydrocarbon oxide are also produced if the cellulose saturated with beta fluid.

 Fault Type: Corona –partial discharge:

Principal Gas: Hydrogen Characteristics:
Hydrogen and methane is also produced due to ejection of corona. Carbon di oxide and carbon mono oxide is include if the corona take place in cellulose.

 Fault Type: Arcing

Principal Gas: acetylene Characteristics:

Acetylene and Hydrogen produced a large amount from arcing and other gas carbon di oxide is also produced in cellulose if the any potential harm is involve and the carbon also exist in the oil.


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Sunday, 12 February 2017

DGA(Dissolved gas analysis) Tool's and Different Fault Occur in Transformer Oil

Interpretation of Gas AnalysisDGA Diagnostic Tools


IEEE published a guideline for the investigation of gases that’s generate in the working transformer popularly known as ANSI ANSI/IEEEC57.104-1978 Standard. This stranded deal with the method of analyzing the, procedure of sampling, separating the gases in the transformer the result and uses of tools.
In 1992, IEEE published another standard guide line knows as IEEE Std C57.104-1991 and this instrument focused on the DGA result. Another guide line is published in 2008 IEEE Std C57.104-2008. I IEC published a guide for the purpose of oil filled in the transformer and the gases sampling and it also work for the detection of free gases and dissolved gases since 1977.
A number of DGA diagnostic instrument which are used now a day found by IEEE C57.104 or IEC60599 guides and as the same way other one which is used basics of these two like national or international guides. As we say before there is a number of tool for guides but in here we will study with the tool that are related to these two IEEE C57.104 or IEC60599. These tow guides IEEE and IEC shows a number of ratio based instruments to find the dissolved gas analysis data. A complete summary is in the current IEEE guide as a recent draft standard (IEEE C57.104-D11d; not approved) of the IEEE guide and the IEC guide is in Table.




Dissolved Gas Analysis instrument are different of their formation, clarity and their correctness. A number of DGA diagnostic tools are simple addition or the one gases ratios for normal levels while others present of multiple gases ratios and each key gas ratio exist in some particular range values.


On-line DGA and Diagnostic Tools


Now a days the online Dissolved gas analysis create a good reputation for his excellent work and incredible measurements and also give wonderful data to the ratio based diagnostic instruments. The expert of DGA feel very easy with the help on line system .they need the snapshot of the condition of transformer and know the present dynamic condition when the transformer is working. Due to on line system introduced new feature which is unbelievable .Snapshots does not indicate diagnostic rate at that ratio. In fact due increase the market DGA in line introduced different combinations. It has also ability to count 8 diagnostic gases. These application are very important they take automate measurement and can show the accurate diagnostic instrument.

Thermal Faults                                    

A large quantity of low molecular mass gases are produce due to decomposition of minerals oil, beta fluid like that methane and hydrogen and a minimum amount of higher molecular mass gas ethylene is also produce. Temperature of beta fluid is increase as a fault, the concentration level of hydrogen gas is increase with respect to the methane gas. So the temperature accompanied the significant quantities of gases which one contain high molecular mass firstly ethane and second one is ethylene. Hydrogen gas and the minimum amount of gas acetylene (C2H2) may be formed due to temperature increase at the upper border of range. The different gases like carbon mono oxide, carbon di oxide, and the vapor of water are produced at the decomposition of beta fluid, thermal cellulose decomposition with another solid insulation at this stage the temperature is very low with respect to the decomposition of oil. The rate formation is increase or decrease with respect to the temperature. The reason is that the paper come to degrade when the temperature low as the beta fluid. All its products in gases form are predict at the normal operating temperature of the transformer.

Low Intensity Discharge for Electrical Faults

Methane and acetylene is produced in small amount when hydrogen is produced at low intensity. As increase the discharge level of two gases acetylene and ethylene the concentration level of these two gases increase sigaficnty.

High Intensity Discharge for Electrical Faults


The produced quantity of acetylene become marked at the temperature reach 700 c to 1800c when the intensity of electrical ejection reaches arcing.
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Saturday, 11 February 2017

DGA (Dissolve Gas Analysis) Testing of Transformer

The things which is separate  between Dissolve Gas Analysis(DGA) with Mineral Oil & with Beta Fluid.


Gas Solubility:
In the given below table it is shown that the solubility of different gases in beta fluid is approximately is same as the conventional transformer oil. It is usually seen that the difference between two fluids is less than 10 percent, which is often due to some poor analysis method and error in the extraction. Now the actually mean is that we can apply same techniques because the gases generated in the transformer oil also solved in the beta fluid at the same extent as that they are in mineral oil. To find the problem it is necessary to find the rate of generated gas and the total amount of key gas present in the transformer. If we find the composition of generated gas then we easily find the source of 

generated key gas and what kind of insulation is involved. 

  
 There are a number of techniques to identify those gases. But the most famous ,reliable and effective method is DGA .In this method first of all we sampling the oil then test these samples to measure the amount of concentration of dissolved gases. It is important to perform DGA of transformer every year and the other important is relate previous results and this will help to predict the problems in the transformer.
ASTM D3613, ASTM D3612, and ANSI/IEEE C57.104, respectively are the standards associate with sampling, testing, and analyzing the results. In this report we analyze the DGA data from field transformers and discuss the method to analyze the faults.

General Theory of Gas Generation

Electrical disturbance and Thermal decomposition are the two basis principal that causes the formation of gases in the operating transformer. There is no required high temperature to produce the gases but the gases generate at normal operating temperature .hydrocarbon molecule are the basic part of mineral oil in the transformer. The decomposition of these molecules is very complex in the thermal or electrical. This figure describe the types of thermal and electrical faults. 


 When chemical reaction take place carbon hydrogen and carbon-carbon bonds break. The fragments of hydrocarbon and hydrogen atom are formed. At the end these fragments attach to each other and formed different gases like hydrogen(H2), methane(CH4),acetylene(C2H2),ethylene(C2H4) and ethane (C2H6).Electric faults (thermal decomposition) generate different gases like carbon mono oxide(CO2),methane(CH4), monoxide (CO), hydrogen (H2) when the cellulose insulation involved in it. These gases are known as the key gasses.
The key gasses are generally assume the combustible (Carbon dioxide is not combustible).If the key gasses are combustible which is present in the transformer indicate the warmly that thermal, electrical or corona faults are exist.
The amount of key gases produce is directly proportional to the temperature and how much amount of material is present at that temperature and the gases produce at the moderate temperature will produces same volume at high temperature. So that the concentration of each gas which is present in the transformer mineral oils used as it and also used to predict the faults  in the transformer.  The concentration level of each gas (in ppm) is taken after analyze the sample and evaluating the result of DGA. 
Its very important that any speedily increase in the concentration of key gases is the indication of some major problem in the transformer. Whenever DGA result shown exceed the key gas concentration level and the normal limits are also increase, then it is favorable to take another sample and analyze that one. After analyze the result compere both of these results which is taken before and after. Now look really concentration increase. The given table is derive ANSI/IEEE C57.104 information.  The concretion level of different gases is given in the table.





There is problem to exceed the concentration level in the transformer so we should apply differ method to determining the seriously problems with in transformer. When we use these techniques the results of these key gases ratio compere with the suggest limits. 

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Friday, 10 February 2017

Gases in Transformer's

Formation of Gases in Transformer's.


The Sample analysis of a Transformer oil is very helpful and predictive to analyze the present condition or health of Transformer .Different gases are formed during normal operation in all transformers and to find the quality of certain key gases ratio then it is easy for operator to predict the issues which is rise in the transformer. Dissolved gas analysis (DGA) is perform of the insulating oil and this analysis help to predict the health of a transformer. Due to some faults inside the transformer generate the gases .These gases generates misbehaver of electrical insulating material and the components that’s relate them. It is very important to verify the identity of these gases to prevent the maintenance problem of transformer.

The advantages of fault gas analyses

·          Advance warning of developing faults
·          Determining the improper use of units
·          Convenient scheduling of repairs
            Monitoring of units under overload 


Why we analyze the Dissolved Gases

A Doctor analyze the blood of patients to predict the disease and this analysis help the doctor to give him right medicine. In the same way the owner of Transformer analyze the dissolved gases in the dielectric fluid to find the problems in the transformer. Corona discharge, arcing in the transformer, localized overheating and general overheating are the major problems in the transformer. Generated gases are dissolved in transformer insulating oil to find the problem it is necessary to find the rate of generated gas and the total amount of key gas present in the transformer. If we find the composition of generated gas then we easily find the source of generated key gas and what kind of insulation is involved.
·         Combustible gas generation theory of transformer.
·         Gas Analysis interpretation.
·         Suggested operating procedures.
·         Dornenberg ratios, and Rogers ratios are diagnostic technique for key gases.

 Limitations:

A number of techniques are in market to find and measure the gases in the transformer. But it is important to note that the detection and measurement of these gases not a science but an art. To find the presence and significance  of gas its totally depend upon on the qualities of the measuring instrument like that the brand, geometry, degree of saturation of various gases in the oil and a number of more qualities.


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Friday, 23 December 2016

Small scale Hydro power

Small scale Hydro power

The small hydroelectric system can produce power rating up to a few mage watt  there are two version of hydroelectric system diversion type and reservoir type. The reservoir type may require a small dam to store water at higher elevation. The diversion type does not require a dam, depend upon the speed of the current to generate electricity.

Diversion type Hydropower

This type of system does not require a dam so it consider more environmentally sensitive.the river for this small hydroelectric system must have stronger enough current for a realistic current generation  the KE entering the turbine KE is given by
KE = .5* mv2    = .5Aspv3t
Pt = KEt/t =      .5Aspv3t

Reservoir Type hydropower

it is either a natural lake at high elevation, then a downstream river or lake created by dam. The system consist mainly  a pen-stock, a turbine and generator. If the water is allowed to flow to lower elevation through the pen stock the potential energy of water converted into KE where some of it is captured by the turbine.
the PE of the water behind the reservoir PE can be found from
 Per WH = mgH

Where
W = the weight of the water, Kg
H = the elevation of the water with respect to the turbine, m;
m = the water mass of the reservoir, kg;
g = the gravitational speed, m/s
if m (kg) is mass of the water of the water entering the pen-stock can be applied to find the input PE of the pen-stock as given by
                          PE pin = mgh
The water flow fw inside the pen-stock is defined as the mass of the water m passing through the pen stock during a time travel t that,
Fw = m/t
PE pin = fw tghH
Which is converted into KE inside the pen-stock. The outpout of KE can be found
KE(out) = .5Apvt pv2
Where
T= the duration of water flow, S;
V = the speed of water exiting the pen-stock,m/s;
Ap = the cross section area of penstock m2
Due to losses in side the penstock such as the water friction, the KE existing the pen-stock KE(output) o\is less then the PE(p_in) at the entrance of the penstock. Thus the efficiency of the penstock is given by
Efficiency = KE/ PEp-in
 The blades of the turbine cannot capture all the kinitaic energy KE existing the penstock.
Cp = KEblade/ KEp-out

Turbine Efficiency

The energy captured by the blade KE is not all captured in to the mechanical energy entering the generator KE due to various losses in the turbine. The ratio of two energies is know as turbine efficiency
The output electrical energy of the generator Eg its equal to its KEm minus the loss of the generator. Thus the generator efficiency ng is defined as
Generator efficiency  = Eg/ KEm
The out put electrical energy as a function of water flow and head.
Eg = fGHt(Cp np nt ng)




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