How Nuclear Power Plant Works ?

 Nuclear Energy Power Plant
The Potential Of Nuclear Energy

how a nuclear power plant works?
Why nuclear?, what is nuclear energy, nuclear and the environment, top 10 facts, learn more, nuclear glossary, the pressurized water reactor(PWR): containment structure, pressurizer, steam generator, control rods, reactor vessel, turbine, condenser, generator., boiling water reactor(BWR).
http://www.cleansafeenergy.org/CASEnergyClassroom/HowaNuclearPowerPlantWorks/tabid/170/Default.aspx



types of nuclear reactors
Boiling water reactor, boiling water reactor, pressurized water reactor, liquid metal fast breeder reactor, control rod structure, reactor core, feedwater pump, steam turbine, condenser. primary loop, secondary loop, primary liquid sodium cooling loop, intermediate liquid sodium cooling loop, water and steam loop to turbine.
http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/reactor.html

nuclear physics fission and fusion
Introduction to nuclear energy, with lecture and discussion : nuclear energy : chemistry analogy, binding energy. fission energy : reactions, resources, status. fusion energy : reactions, resources, wastes.
http://acdisweb.acdis.uiuc.edu:16080/NPRE201/coursematerial/nuclear_physics/lecture20.html


nuclear power reactors
Several components common to most types of reactors : fuel, moderator, control rods, coolant, pressure vessel of pressure tubes, steam generator, containment. several different types of reactors : pressurised water reactor, boiling water reactor, pressurised heavy water reactor, gas cooled reactor, light water graphite reactor, fast neutron reactor. floating nuclear power plants, primitive reactors, primary coolants, water, helium, carbon dioxide, sodium, lead, molten fluoride salt, heat transfer for different primary coolants, use of water for cooling.
http://www.uic.com.au/nip64.htm

the story of nuclear energy fission and fusion
Formula by famous scientist Albert Einstein, the equation says, Einstein's voice explaining. nuclear fission, nuclear fusion : deutrium, tritium, neutron, helium, energy.
http://www.energyquest.ca.gov/story/chapter13.html

video power plant tour
Take a virtual power plant tour, what you will need for the tour, tour tips, start the tour : view the entire tour from start to finish, start in the fuel section, start in the water section, start in the electricity section.
http://www.srpnet.com/education/tour/

inside a nuclear reactor
Controlling, coolant, fuel, moderator, shield, steam, electricity, test your knowledge.
http://schools.matter.org.uk/Content/NuclearReactor/NuclearReactorApplet.html


energy information administration
Nuclear power plants operating in the united states as of december 31, 2005, EIA data on reactors, EIA data on nuclear generation, nuclear and uranium forecasts, nuclear regulatory commission.
http://www.eia.doe.gov/cneaf/nuclear/page/at_a_glance/reactors/states.html

the virtual nuclear tourist, nuclear power plants around the world
Current hot topics, terrorism concerns, location, private spent fuel storage, russian enriched fuel, effects of low levels of radiation, transportation of nuclear waste, decommissioning of nuclear plants, reprocessingm advanced reactors, inside the nuclear power plants, US locations plant maps, plant status events assesment operational experience NRC plant assesments reactor oversight, sample preliminary safety analysis report, world locations plants, web searches for specific us power plants.
http://www.nucleartourist.com/

Pressurized Water Reactors
http://www.nrc.gov/reactors/pwrs.html

nuclear power plant operations
Reactor system, Pressurized Water Reactor System, Protective Barriers.
http://www.hsem.state.mn.us/HSem_view_Article.asp?docid=251&catid=3

The History and Inventor of Nuclear Power plant

In 100 BC an Alexandrian Greek speaking philosopher by the name of Ctesibius
invented the piston - pump.
In 1606, Italian scientist Giovanni Batista della Porta of Naples heated water in a flask until the water turned into steam.

In the 1600's several scientists continued work on steam powered pumps. Robert Boyle proposed the steam engine in 1678.

In 1680's a gunpowder explosion was used to heat water. Jean de Hautefeuille tried to up water, and Dutch astronomer Christiaan Huygens tried a piston in a

cylinder.

In 1712, Thomas Newcom and John Calley built their first successful steam engine.

In 1769 Nicholas Cugnot built the first mechanically propelled road vehicle

In 1789 Uranium was discovered by Martin Klaproth, a German chemist, and named after the planet Uranus.

In 1895 Ionising radiation was discovered by Wilhelm Rontgen by passing an electric current through an evacuated glass tube and producing continuous X-rays.
In 1896 Henri Becquerel found that pitchblende an ore containing radium and uranium caused a photographic plate to darken. He went on to demonstrate that

this was due to beta radiation electrons and alpha particles helium nuclei being emitted.
In 1896 Pierre and Marie Curie gave the name 'radioactivity' to this phenomenon.
In 1898 isolated polonium and radium from the pitchblende. Radium was later used in medical treatment.
In 1898 Samuel Prescott showed that radiation destroyed bacteria in food.
In 1902 Ernest Rutherford showed that radioactivity as a spontaneous event emitting an alpha or beta particle from the nucleus created a different element.

He went on to develop a fuller understanding of atoms.

In 1905 This was the first experimental confirmation of Albert Einstein's paper putting forward the equivalence between mass and energy, which had been

published.

In 1919 he fired alpha particles from a radium source into nitrogen and found that nuclear rearrangement was occurring, with formation of oxygen.
Niels Bohr was another scientist who advanced our understanding of the atom and the way electrons were arranged around its nucleus through to the 1940s.

In 1911 Frederick Soddy discovered that naturally-radioactive elements had a number of different isotopes radionuclides, with the same chemistry.
In 1911, George de Hevesy showed that such radionuclides were invaluable as tracers, because minute amounts could readily be detected with simple instruments.

In 1932 James Chadwick discovered the neutron.
In 1932 Cockcroft and Walton produced nuclear transformations by bombarding atoms with accelerated protons.

In 1934 Irene Curie and Frederic Joliot found that some such transformations created artificial radionuclides.
The next year Enrico Fermi found that a much greater variety of artificial radionuclides could be formed when neutrons were used instead of protons.

In January 1939 Frisch then confirmed this figure experimentally
1939 developments sparked activity in many laboratories. Hahn and Strassman showed that fission not only released a lot of energy but that it also released additional neutrons which could cause fission in other uranium nuclei and possibly a self-sustaining chain reaction leading to an enormous release of energy.

In 1900 Work on radioactive minerals found in central Asia began
Enrico Fermi (1901-1954), an Italian American physicist who won the 1938 Nobel Prize in Physics .
Otto Hahn (1879-1968), a German physical chemist who won the 1944 Nobel Prize in Chemistry.
Enrico Fermi (1901-1954), an Italian American physicist who won the 1938 Nobel Prize in Physics  Otto Hahn (1879-1968), a German physical chemist who won the

1944 Nobel Prize in Chemistry Lise Meitner (1878-1968), an Austrian Swedish physicist Hyman G. Rickover (1898-1986), a Polish American naval officer

Discovering Fission Nuclear fission involves the splitting of an atomic nucleus, leading to the release of large amounts of energy. Nuclear fission was discovered in Germany in 1938 by Otto Hahn after he had bombarded uranium with neutrons and observed traces of radioactive barium. Meitner and her nephew, Otto Robert Frisch, were able to calculate the enormous energy that would be released in this type of reaction. They published their

results early in 1939. Nuclear fission was quickly verified in several laboratories.
Danish physicist Niels Bohr soon demonstrated that the rare uranium 235 (U-235) isotope is much more likely to fission than the common uranium 238 (U-238) isotope, which makes up 99.3 percent of natural uranium.

In 1909 St Petersburg Academy of Sciences began a large-scale investigation
1917 Revolution gave a boost to scientific research and over 10 physics institutes were established in major Russian towns, particularly St Petersburg, in the years which followed.

In the 1920s and early 1930s many prominent Russian physicists worked abroad, encouraged by the new regime initially as the best way to raise the level of expertise quickly. These included Kirill Sinelnikov, Pyotr Kapitsa and Vladimir Vernadsky.

In 1931  Kirill Sinelnikov returned from Cambridge to organise a department at the Ukrainian Physico-Technical Institute FTI in Kharkov which had been set up in 1928.

In 1933 became the Department of Nuclear Physics under Kurchatov with four separate laboratories.
In 1940 saw great advances being made in the understanding of nuclear fission including the possibility of a chain reaction. At the urging of Kurchatov and his colleagues, the Academy of Sciences set up a "Committee for the Problem of Uranium" in June 1940 chaired by Vitaly Khlopin

In June 1942 the US Army took over process development, engineering design, procurement of materials and site selection for pilot plants for four methods of making fissionable material.

In August 1943 an agreement was finally signed by Mr Churchill and President Roosevelt in Quebec.
In December 1951 The first nuclear reactor to produce electricity (albeit a trivial amount was the small Experimental Breeder reactor (EBR-1) in Idaho, in

the USA, which started up.

In October, 1956 It began producing about 90 megawatts of electric power.
In December 2, 1957, on the fifteenth anniversary of the first controlled nuclear chain reaction, the Shippingport Atomic Power Station in Shippingport,

Pennsylvania, became the first full-scale commercial nuclear power plant in the United States.

In September, 1959 The Dresden Nuclear Power Station, completed by Commonwealth Edison.
In 1973, forty-two plants were in operation producing 26,000 megawatts, fifty more were under construction, and about one hundred were on order.
In 1986, more than one hundred nuclear power plants were operating in the United States, producing about 60,000 megawatts of power.

In December 1993, the total number of nuclear power plants in the United States is 109, collectively producing 610 billion kWhs of electricity.

10 Largest Nuclear Power Plants In The World

1. Kashiwazaki-Kariwa Nuclear Power Plant 8,212 Mega Watts

Niigata prefecture, Japan

Towns of Kashiwazaki and Kariwa

Has seven nuclear reactors. 

The station is about 220 km northwest of Toyko

The plant, owned by Tepco, was built in 1985

2. Uljin Nuclear Power Plant 6,157 Mega Watts

Gyeongsangbuk-do province, South Korea

Has six nuclear reactors have been built to withstand 6.5 magnitude earthquakes

3. Yonggwang Atomic Energy Plant 6,137 Mega Watts

Yonggwang, South Korea

Has six nuclear reactors that each produce over 900 megawatts of power. 

The plant, which began operation in 1978

4. Zaporizhzhia Atomic Energy Plant 6,000 Mega Watts

Enerhodar, Ukraine

The plant has six generators that The world’s worst nuclear disaster. About 400 times more radiation than the atomic bomb dropped over Hiroshima during World War II.

5. Gravelines Nuclear Power Plant 5,706 Mega Watts

Gravelines, France

The six reactors came online between 1980 and 1984 and the plant recently completed quite a milestone

It generated its 1000 billionth kilowatt hour of energy. 

Local fish farmers use the water that carries waste heat from the plant to help raise European sea bass and other fish. 

The warm water helps the fish grow faster.

6. Paluel Nuclear Power Plant 5,528 Mega Watts

Normandy, France

The second largest of its kind in France with four reactors that generate over 1,300 megawatts of power each hour. 

The rest of the country’s nuclear stations are located away from the coast and get their cooling water from rivers.

About 11 of the 15 inland plants have evaporative cooling towers to lessen the need for fresh water. 

7. Cattenom Nuclear Power Plant 5,448 Mega Watts

Cattenom, France

The station is owned by Electricite de France (EDF),Europe’s biggest power generator and the world’s second biggest utility company. 

In April, about 2,000 people protested outside the site along with thousands across the country over the dangers of nuclear power.

France is one of the largest consumers of nuclear power, with 75 percent of its electricity coming from the source. 

8. Bruce Nuclear Power Plant 5,090 Mega Watts

Inverhuron & Tiverton, Canada

The largest nuclear plant in North America. 

The station takes up 2,300 acres near Lake Huron in Ontario.

It has eight nuclear reactors, but only six are operational. 

The company is on track to restart the other two reactors by 2012, adding another 1,500 megawatts of power to the station. Once all eight are operational, the station will become the world’s second largest nuclear plant by capacity.

9. Oi Nuclear Power plant 4,710 Mega Watts

Fukui prefecture, Japan

Owned by Kansai Electric Power Company (KEPCO)

One of Japan’s largest  utilities. 

The plant houses four nuclear reactors that each generate over 1,000 megawatts of power per hour. 

KEPCO has come under fire in the past for incidents at its nuclear plants. 

In 2004, five employees were killed at its Mihama nuclear plant from a burst of steam, which was blamed on neglected safety checks. 

In 2006, two employees were also injured in a plant fire.

10. Fukushima Daiichi 4,696 Mega Watts

Okuma, Japan

The world’s 10th largest nuclear station before Japan’s catastrophic earthquake and tsunami. 

The plant started operations in 1971 and has six nuclear reactors, which were badly damaged on March 11. 

Tepco had planned two more reactors at the site, but the company now plans to abandon these and scrap the site entirely.

Most of the reactors are old boiling water reactors (BWR) based on a GE design. 

In February, Tepco admitted to the Japanese nuclear safety agency that it had submitted false inspection and safety reports.

Nuclear Power Plant Advantages and Disadvantages

What Are Advantage and Disadvantages of Nuclear Power Plant

Advantages of A Nuclear Power Plant
1. Breeder reactors create more usable fuel than they use.
2.A nuclear aircraft carrier can circle the globe continuously for 30 years on its original fuel while a diesel fueled carrier has a range of only about 3000 miles before having to refuel.
3.Current nuclear waste in the US is over 90% Uranium. If reprocessing were made legal again in the US we would have enough nuclear material to last hundreds of years.
4.They can be sited almost anywhere unlike oil which is mostly imported.
5.Almost 0 emissions (very low greenhouse gas emissions.
6.A single nuclear reactor can produce a substantial amount of power. A nuclear reactor produces much more power per unit weight of nuclear fuel than conventional energy sources like coal and oil. The production of nuclear power does not release carbon dioxide into the atmosphere and hence does not contribute to global warming.
7.Nuclear power plants don't take up much space. This allows them to be placed in already developed areas and the power does not have to be transferred over long  distances.
8.Nuclear power plants already exist and are available worldwide. So in comparison to, for example, nuclear fusion, the technology does not have to be developed first.
9.Another advantage of nuclear power is that nuclear energy is by far the most concentrated form of energy, so it can be produced in large quantities over short periods of time.
10.Nuclear power generation does emit relatively low amounts of CO2. Nowadays global warming because of the greenhouse gases is a hot topic. The contribution of nuclear power to global warming is relatively little.

Disadvantages of A Nuclear Power Plant
1.Mishaps at nuclear plants can render hundreds of square miles of land uninhabitable and unsuitable for any use for years, decades or longer, and kill off entire river systems
2.Early nuclear research and experimentation has created massive contamination problems that are still uncontained. Recently, for instance, underground contamination emanating from the Hanford Nuclear Reservation in Washington State in the U.S. was discovered and threatens to contaminate the Columbia River
3.Nuclear plants are more expensive to build and maintain.
4.Nuclear reactors are particularly vulnerable to terrorist attacks. The construction cost of a nuclear reactor is high. It takes a significantly long time to construct nuclear plants. At present, the reserves of uranium, a critical nuclear fuel, are limited in the world. Nuclear plant workers may be exposed to high levels of radiation, which can cause cancer and other ailments.
5.Nuclear reactors only last for about forty to fifty years, so where they are extremely productive, they break down and are costly to replace.
6.It is a high risk power supply. Of course a nuclear power plant has a very high security standard, but it is impossible to build a plant with a 100% security. We all know what horrible consequences there will be if an error or accident occurs in this plant.
7.A nuclear meltdown can often occur which will release massive amounts of radiation into the community.
8.nuclear energy can create more problems than they solve. Nuclear mishaps do not happen very often, but when they do, it creates a catastrophe that can damage the country and surrounding area for years to come.
9.The technology used for generating nuclear power can also be used for producing nuclear weapons. The country of North Korea is a classic example of this. The technology still does not exist to use nuclear power in relatively smaller devices like automobiles.
10.These plants also consume large amounts of water, which can damage marine life and affect the wildlife population in the area.


Free PDF Download Advantages and Disadvantages
Energy & the Environment
Advantages Nuclear fuel does not make harmful greenhouse gases.  You only need a very small amount of nuclear fuel to make a lot of energy  Disdvantages The waste that is produced when using nuclear fuel is radioactive and very harmful.  It needs  to be disposed of  carefully  Nuclear power stations are at risk from terrorist attack and sabotage.  World uranium supplies may run out in about 50 years.

Free Download The Danger of Nuclear Power Plant

The Risk and Danger of Nuclear power plant should everyone know why? because its affects in the human race, our health, our family etc. by way of teaching or learning I have here list of a free download pdf file from different site.
A dangerous waste of time greenpeace
The nuclear power industry is attempting to exploit the climate crisis by aggressively promoting nuclear technology as a “low-carbon” means of generating electricity. Nuclear power claims to be safe,
cost-effective and able meet the world’s energy needs. But nothingcould be further from the truth.

Understanding radiation
Radioactive materials are composed of atoms that are unstable. An unstable atom gives off its excess energy until it becomes stable. The energy emitted is radiation. Radiation has a cumulative effect. The longer a person is exposed to radiation, the greater the risk.


Nuclear Facts
Despite the fact that a national global warming emissions cap-and-trade system would materially assist the economic case for nuclear power, the nuclear industry has not been willing to openly advocate for such a system.

Nuclear Power Plant Security
Physical security at nuclear power plants involves the threat of radiological sabotage adeliberate act against a plant that could directly or indirectly endanger public health and safety through exposure to radiation.

Natural Disasters and Safety Risks
A typical nuclear power station will be connected to the electric grid through three or more transmission lines. Should these power lines go down or a regional electrical grid collapse occur, onsite emergency generators diesel, gas turbines or in few cases hydroelectric dams are designed to automatically start with manual
backup capability.

Radiation Risks and Realities
These findings allow us to use radioactive materials for beneficial purposes, such as generating electricity and diagnosing and treating medical problems. For these many benefits, excessive radiation exposure can also threaten our health and the quality of our environment.

The Tolerability of Risk
But in fact many people are bothered about nuclear power and other industrial risks and have become more so during the years since Sir Frank Layfield wrote his report.

How Does Electric Tractions Works? Question and Answer

Electric Traction Theory
Steam Locomotive, Diesel Engines, Electric traction, Advantages, Electrical transmission, which is usually applied to high power units, has following advantages, The Direct and Alternating Current.

what is electric traction?
electric Traction means to use electic motors for railway service, Act of drawing or being drawn is known as traction.If electric supply is used for driving a locomotive, the system is known as electric traction.Electric traction may be A.C. or D.C. powered.e.g.600V dc is given to tramways and trolley buses.

ELECTRIC TRACTION
The electric locomotive and electric motor coach may be regarded as natural developments that have followed steam traction. New conditions have set new standards in railway travel. This is exemplified in the rapid development of electric suburban train services for the new built-up areas spreading in all directions round large cities.

Electric Traction Drives
This page describes the way electric motors on locomotives and multiple units drive the axles and wheels. See also the Electronic Power, Multiple Unit Operation, DC Traction Motor Systems and Electric Traction Glossary pages.

Answer tips/answer samples of What is electric traction?
Electric traction systems use DC motors, but nowadays, some people tend to use magnetic traction instead of electric ones.

ELECTRIC TRACTION FOR AUTOMOBILES - Free PDF download
a comparison concerning electric traction drives for passenger cars is given. Electric traction drives presently available on the market are analyzed and future developments are described.

Power Supply Installation in Electric Traction - Free PDF download
The book on "Power Supply Installation in Electrical Traction" was brought out by Institution of Railway Electrical Engineers (IREE) long back. Since, lot of changes have taken place in the field of Power Supply Installation, it has become necessary to incorporate the changes in this volume. Few additions and modifications in the field of Power Supply Installations are included in this book.

Question and Answer of Electric Traction

1. Overall efficiency of steam locomotive system is close to answer 5 to 10 percent
2. Maximum horse power of steam locomotive is answer 1500
3. The efficiency of diesel locomotives is nearly answer20 to 25 percent
4. The range of horsepower for diesel locomotives is 1500 to 2500
5. What motor is used in tramways? answer DC series motor
6. The advantages of electric braking is It prevents wear of track
7. What is the braking system on the locomotives answer Regenerative breaking on electric locomotives
8. What is the coefficient of adhesion highest? when answer the rails are dry
9. The estimated speed of the train, including the time of stop at a station, in addition to the actual running time between stops, is called its answer Schedule speed
10. Which of the following types of services consume the least specific energy? Main line service
11. Locomotives have two bogies with two driving axles with individual drive motors.
12. A composite system is made up of answer single phase power received is converted into DC or three phase power AC system
13. For 600 volts DC line for tram cars what is the correct voltages Track are connected to negative of the supply
14. Free running and coasting periods are generally long in case of which of the following services? answer Main line service
15. A train runs at an average speed of 50 kmph between stations situated 2.5 km apart. The train accelerates at 2 kmph and retards at 3 kmph. Speed time curve may be assumed to be trapezoidal. The maximum speed with these parameters will be answer 57.75kmph
16. Suri transmission is answer Hydro mechanical
17. When a locomotive for Indian Railways is designed as WAMI, what does the letter W indicate? answer The locomotive is to run on broad gauge track
18. The main differece between speed time curve of main line service as compared to suburban services lies in answer longer free running periods, longer coasting periods and shorter acceleration and braking periods

Transformer Built In Protection and Cooling Tutorials

Protection Devices Built In For Safe Operation of A Transformer

Conservator

It is a sort of a drum, mounted on the top of transformer. A level indicatoris fixed to it. Conservator is connected through a pipe to the transformer containing oil. This oil expanse and contracts depending upon the heat produced so the oil level in the conservator rises and falls. Pipe connected to the conservator is left open to the atmosphere through a breather so that extra air any go out or come in.

Breather

Is is a box containing calcium chloride to absorb moisture of air entering the conservator as it sis well known fact that the insulating property of the transformer oil is lost even if a small amount of moisture enters in it, so the dry air is allowed to pass in through this breather.

Temperature Gauge

It is fitted to a transformer which indicates the temperature of transformer oil.Explosion Vent

It protects the transformer tank from the gases induced by any type  of short circuit in the transformer.

Pipes

These are fitted for cooling the transformer oil. The hot oil circulates through these pipes where it becomes cool due to the air touching.

Important Facts About Transmission and Distribution Transformer

1. Eddy current losses in a transformer are minimised by laminating the core, the lamination being insulated from each other by a light coat of core plate varnish.

2. The basic property of the transformer is that it changes the voltage level of an alternating current signal without changing power, frequency or shape.

3. The primary and secondary voltages are 180 degree out of phase in transformer.

4. Eddy current lossesin transformer core are reduced by decreasing the thickness of laminations.

5. The resistance of low voltage side of a transformer is less than the resistance of its high voltage side.

6. The efficiency of a transformer is normally in the range of ninety ot ninety eight percent.

7. The reactance of transformer is determined by its leakage flux.

8. The principle of working of a transformer is mutual induction.

9. Transformer is used to change the valuesof voltage.

10. The path of the magnetic flux in a transformer has low reactance.

11. Electric power is transformed from one coil to the other coil in a transformer magnetically.

12. Ideal transformer assumptions do not include zero reactance of windings.

13. Preferably, the resistance between the primary and the secondary of a transformer should be as low as possible.

14. The main function of the iron core in a transformer is to decrease the reluctance of the magnetic path.

15. Magnetic circuit is common in the two windings of a transformer.

16. A transformer operates at power factor depending on the power factor of the load.

17. The lamination are made from nickel alloy steel stampings.

18. The steel for construction of transformer core is made so as to have high permeability and low hysteresis.

19. The special silicon stell in used for laminations because hysteresis losses are reduced.

20. Power transformer are designed to have maximum efficiency at near full load.

Cooling Of Transformer

Natural Cooling

The cooling is provided through natural circulation of air. The surface area of the core and the transformer winding are sufficient to dissipate the heat generated. It is used for small transformer from ten kva to fifteen kva.

Natural Oil Cooling

The transformer is placed in tank filled with oil known as transformer oil. The oil used in the tank not only helps cooling the transformer but also provides insulating for the winding. The oil takes the heat produced by the transformer, the oil circulate through the pipes and tank. The hot oil becomes lighter in weight and goes up from where comes down through pipes to the bottom of the tank after cooling. The oil level should never fall below the upper ends of pipes.

Oil Blast Cooling

In this method radiator tanks are provided to the side walls of the main tank. The oil circulators through these radiators from the main tank. The radiator tanks are cooled by air blast. The system of cooling is known as oil blast type. It is used for transformer rated above five hundred kva.

Force Water Cooling

The winding of transformer is placed inside the tank containing oil and cold water is passed through the copper pipe spiral kept in the transformer oil. The cold water absorbs and carrier away the heat of the oil. The pressure of the water is not kept greater than the pressure of the oil in the tank because in case of leakage in the pipe, the water will enter into the oil. It is used for transformer having output greater than five hundred KVA.

Force Air Cooling

In this method the air is first filtered to eliminate moisture and dust particless and this filetered air under pressure is forced to passed through the winding care of the transformer and the dusts provided in them. This method is used where there 

is a scarcity of water.

Power Transformer Tutorials Links

Tutorials on Electrical Power Factor Correction

All About Power Factor Links

Power Factor Meter
A direct reading instrument for measuring power factor. It is provided with a scale graduated in power factor.

Power Factor Relay
Power system device function numbers. A relay that operates when the power factor in an alternating current circuit rises above or falls below a predetermined value.

Power Feeder
A feeder supplying principally a power or heating load.

Power Frequency
The value of frequency used in the Electrical power system, such as 50 hz or 60 Hz.

Power Inverter
A converter unit in which the direction of average power flow in from the DC circuit to the alternating circuit.

Power Monitor
A functional module that monitors the status of the primary power source to the system, and signals when that power has strayed outside the limits required for reliable system operation. Since most systems are powered by an alternating current source, the power monitor is typically designed to detect dropout or
brown out conditions on alternating current lines.

Power Factor Question and Answer

1. If a current of 10 amperes at a power factor of 0.8 lagging is taken from 250 Volt alternating current supply, the reactive power of the system will work out to be 1500 VAR.
2. Many industrial tariffs penalise consumers whose power factor falls below 0.8.
3. Power factor improvement may be achieved the use of synchronous motor.
4. One of the reasons for improving the power factor is to decrease the reactive power.
5. The power factor of incadescent bulb is unit.
6. The power facotor of an inductive circuit can be improved by connecting a capacitor to it in series.
7. The capacitor of power factor correction are rated in terms of KVAR.
8. In an alternating current circuit, a low value of with reactive volt ampere compared with watts indicates high power factor.
9. It is not easy to find the value of impedance for a parallel circuit but power factor can easily be obtained as a ratio of active current to line current.
10. In a series circuit consisting of resistance and reactance, power factor is a defined as the ratio of resistance to impedance.
11. In pure reactive circuit, the power factor is zero.
12. Power factor is defined as the ratio of watts to volt ampere.
13. For a parallel circuit consisting of resistance and reactance the value of power factor is the ratio of impedance to resistance.
14. The power factor of an alternating current circuit containing both a resistor and a conductor is between 0 - 1 leading.
15. In a given circuit when power factor is unity the reactive power is zero.
16. A poor power factor results in overloading of transformer as well as alternators.
17. For the same load, if the power factor of load is reduced, it will draw more current.
18. The power factor of the magnetizing component of a transformer is always leading.
19. Another reason for improving the power factor is to avoid poor voltage regulation.
20. The advantage of using static capacitors to improve the power factor is that they are almost loss free.

Causes of Low Power Factor
1. Arc lamps and industrial heating furnaces are typical of low power factor operating equipments.
2. During the night time when load is less the supply voltage increase which in turn, causes the magnetising current of transformers and motors to increase. Therefore, the power factor at which the system operates becomes low.
3. Mostly alternating current motors are of induction type. These operate on low lagging power factor.

The Adverse of Low Power Factor
1. With low p.f. cost of generation and transmission increases due to increase in current and use of thicker wires and bigger switches.
2. Low pf. makes the voltage regulation of generators, transformer and transmission line greater.
3. For a given p.f. to be supplied, the current is increased due to low p.f. in causes increase in copper losses, and decreases the efficiency of both apparatus and supply system.
4. With low pf generators, transformer, swithes transmission lines become over loaded.

Electrical Transformer tutorials Current Potential and Auto tutorials

Current Transformers The primary of this transformer consists of a few turns or even a single turn to carry the current to be measured and is connected in series with the main circuit. The secondary winding with large number of turns supplies a reduced current to the ammeter. The meter scale is calibrated directly in terms of the primary circuit current.The core is worked at low flux density so that, at all loads, secondary current is a constant ratio of the main circuit current. When the cuurent is flowing in the primary circuit, the secondary circuit should not be opened. In that case high voltage may be induced in the secondary and the core may become over saturated, heated up and thereby damage the magnetic properties permanently.

Potential Transformer
This is used to reduce the primary voltage to a safe value for operation of voltmeter and other instrument. Primary is connected to the H.T. to be measured and the secondary to a voltmeter. It is so designed that the ratio of primary to secondary is constant throughout. To limit the short circuit in case of failure of the transformer, limiting resistances are placed in series with the H.T. winding.

Auto-transformer works on the priciple of self Induction
It has only one winding which performs the function of both primary and secondary winding. As in ordinary transformer, the transformation ratio in autotransformer, is also equal to the turns ratio.
In case of step down transformer, the complete winding acts as primary winding while the tapped section of this winding works as secondary winding. In the step up transformer, the whole winding works as secondary winding and its there is much saving of copper. These transformers are used as regulating transformers where only a small variation of voltage is required. It is mainly used for starting and speed control of induction motors. It suffers from a disadvantage that the two windings are not electrically separate and in case of failure of insulation between the two, either a sever shock may be felt on the low voltage side.

Various parts of a Transformer
Primary winding
Secondary winding
Oil level
Conservator
Breather
Drain cock
Tube for cooling
Transformer Oil
Earth Point
Explosion vent
Buchhol's Relay
H.T. Terminals
L.T Terminals


Free Pdf file about the kinds of Transformer

Current Transformers
Current transformers are used in electrical grids for measurement and protective applications to provide signals to equipment such as meters and protective relays by stepping down the current of that system to measurable values.

Instrument Transformers
Technical Information and Application Guide

Selecting Current Transformers
As engineers, we are aware that electrical power systems have grown. How much have they grown?

Current Transformer Principles and Operation
Used with watt transducers enable the owner to control demand as well as monitor building and/or tenant power consumption. When CT's are used with Current Transducers, the result is an excellent method of diagnosing the performance of fans,pumps, chillers.

Potential Transformer
Voltage transformers connected line-to-ground cannot be considered to be grounding transformers and must not be operated with the secondaries in closed delta because excessive currents may flow in the delta.
VOLTAGE TRANSFORMERS
Potential transformer are so small that they may be neglected for protective-relaying purposes if the burden is within the "thermal" volt-ampere rating of the transformer. This thermal volt-ampere rating corresponds to the full-load rating of a power transformer.

Auto Transformer
The currents drawn by these two windings are out of phase by 180◦. This prompted the use of a part of the primary as secondary. This is equivalent to fusing the secondary turns into primary turns.

Transformers vs. Autotransformers
A transformer converts audio from one voltage and impedance to a different voltage and impedance. Transformers are passive which means they do not require a  power supply to operate.