Trining Report PTPS,Panipat ( Pardeep Malik)

(FOR PARTIAL FULFILLMENT OF REQUIREMENT FOR AWARD OFTHE DEGREE IN ELECTRICAL ENGINEERING

FROM D.C.R.U.S.T., MURTHAL)

SUBMITTED BY:- SUBMITTED TO:- Raj Singhmar DEPT OFELECTRICAL ENGG. ELECTRICAL ENGG.ROLL NO. – 2K6/EE/293-D D.C.R.U.S.T., MURTHALD.C.R.U.S.T., MURTHAL

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ACKNOWLEDGEMENT

The present report would not have been possible without the help which I have received from various quarters. I shall be failing in my duty if don’t acknowledge the help and guidance of these squares.

1st of all would like to thank the management of PANPIPAT THERMAL POWER STATION, PANIPAT for allowing me to their plant for my training.

I express my sincere thank to all those at P.T.P.S., PANIPAT who have helped me during my summer training 2007. I am obliged to department of training at electrical maintenance division-IV

Er. D.K. Sharma (XEN of EMD-VIII)Er. Ashok Kumar (AE EMD-VIII)Er. O.P. Dhingra (JE 1st EMD-VIII)Er. Ashok Kumar Bhardwaj (XEN of training dept.)

MANOJ SAINI2K6/EE/293-DELECTRICAL ENGG.D.C.R.U.S.T., MURTHAL

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CERTIFICATE

SHAWET MITTAL submitted my training report detailing the work done during six weeks training at P.T.P.S., PANIPAT. This report written by him from various sources has been fully acknowledged.

NAME : Rajesh singhmarROLL NO. : 2K6/EE/293-DDIVISION : VIIIDATE OF COMMITMENT : 22-06-2007DATE OF COMPLETION : 01-08-2007

Mr. MANOJ SAINI has worked under my supervision during training period I have read this report, it meets our exceptions and accurately work done by him.

Er. D.K. Sharma Er.Ashok KumarXEN EMD VIII AEE EMD VIIIP.T.P.S., PANIPAT P.T.P.S., PANIPAT

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HISTORY AND EVOLUTIONOF THERMAL POWER PLANTS

IN INDIA

The history of thermal power plants in India dates back to year 1899 when the first station was commissioned in Calcutta with an installed capacity of 1000KW. During the first two decades the twentieth century steam power generation plants at Kanpur, Madras, and Calcutta of capacities 2170KW, 9000KW, and 1500KW respectively were commissioned. By the end of 1920s the total installed capacity of thermal power plants was 50MW. Thus figure reached 1000MW in year 1951.

Efforts for organizing the power supply in industry in a rational manner began only after the independence. With the launching of first five years plan in year 1951 installed generating capacity increased by 200MW. During this five years plan the total thermal power generating capacity raised up to 1520MW.

If we concentrate on the history of thermal power plants in Haryana we find that the first plant ay Faridabaad in year 1960. after that five units of 60MW each were installed in years 1979, 1981, 1982, 1983, and 1985 respectively. Two units of capacity 110MW each were installed at PANPIPAT THERMAL POWER STATION, PANIPAT in year 1979 & 1980. After that the two more units of same capacity were installed in year 1985 & 1987. PANPIPAT THERMAL POWER STATION, PANIPAT also commissioned 5th & 6th unit of 210MW each in the year 1989 & 2001. PANPIPAT THERMAL POWER STATION, PANIPAT also commissioned 7th & 8th unit of 250MW each in the year 2004 & 2005.

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KALAM FOR CONSORTIUM APPROACH IN POWER SECTOR

PANIPAT, oct,16 (PTI): President A.P.J. Abdul Kalam, today said there was a need for adoption for of a consortium approach by the Railway and Coal minister and the state governments to ensure quality and uninterrupted power of PANIPAT THERMAL POWER STATION, PANIPAT to the nation here. Kalam said that the Haryana government can take a lead in the use of new technologies in its future plans.

Kalam said that new technology options like integrated coal gasification and solar integrated combined cycle were also being explored. “owever, there was a need to implement these technologies at the earliest so that we could have better coal, higher efficiency of the plant, reduced transportation load and minimum impact on the environment”, he said.

The President said that with a view to minimizing the impact of coal based plants on environment, a power plant using super critical technologies with higher steam parameters was being set up for improving efficiency.

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CONTENTS

1. INTRODUCTION TO PANIPAT THERMAL POWER STATION, PANIPAT

2. LOCATION OF THERMAL POWER STATION

3. PLANT LAYOUT

FUEL AND ASH HANDLING CIRCUIT AIR AND GAS CIRCUIT FEED WATER AND STEAM FLOW CIRCUIT COOLING WATER AND STEM FLOW CIRCUIT

4. TRANSFORMER

5. H.T. MOTORS AND L.T. MOTORS (AND THEIR SPECIFICATION)

6. SWITCHYARD COMPONENTS

7. OPERATION OF CIRCUIT BREAKERS

8. DISTRIBUTION SYSTEM

9. BUS BARS

10. EFFICIENCY OF THE PLANT

11. SUPERCRITICAL TECHNOLOGY

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PANIPAT THERMAL POWER STAION, PANIPAT

(A UNIT OF HARYANA POWER GENERATION CORPORATION LTD.)

INTRODUCTION

The PANIPAT THERMAL POWER STATION, PANIPAT comprising of 8 generating units. Four 110MW each, two generation units of 210MW each and two generation units of 250MW each.

The plant is located about 9km away from Panipat on Panipat-Asandh road near Aassan village. The station area is 1870 acres, out of which 630 acres is occupied by the power plant, 400 acres are for residential colonies and rest of 840 acres are being used for the disposal of ash of the combusted coal.

The inputs of the plant are mainly coal and water. The water of the plant is usually gotten available from near by Yamuna canal through a channel. The water is first purified and demineralised before sending it to the boilers being used for stem production. Coal is gotten at the plant in railway wagons that are unloaded mechanically by tilting the wagons by tippler. Coal is first crushed to powder state before supplying it to the boilers.

The total investment on the plant has been 2,500 crore.

Daily coal required in thermal is 15,000 metric tone.

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The salient features of plant are as under:-

Unit no.

Date of commissioning

Capacity(MW)

HEIGHT OF COOLING TOWER(m)

1 01-11-1979 110MW 123.52 27-03-1980 110MW 123.53 01-01-1985 110MW 143.54 11-01-1987 110MW 143.55 28-03-1989 210MW 1406 04-07-2001 210MW 1407 16-10-2004 250MW8 02-02-2005 250MW

LOCATION OF THERMAL POWER STATIONThere are various factors whose consideration is essential

while deciding the location of any thermal power plant.Two essential inputs is that water and fuel must be easily

available. For getting the coal supply, the place should be connected by rail or road. The raw water should be available near the site. Future expansion flexibility is also taken in to account.

COAL AND ASH HANDLING PROCEDURE

Coal delivery by wagons. Uploading by tipplers. Treatment by crusher. Pulverizing mill treatment supply of pulverized coal to the

furnace. The supply of the pulverized coal to the burner is controlled

by the flow of air. When the control system senses a higher demand, more air is supplied to carry additional coal to the burner.

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AIR AND GASAir is fed in to furnace through F.D. (force draught) fans.

Air being supplied to the furnace is passed through air pre-heater.A P.A. (primary air) fan provides air that carries coal along with it and is fed in to the furnace. F.D. fan supplies hot air for combustion. I.D. (induced draught) fan is installed near the bottom of the chimney. The burned gases are sucked out of the boiler, thus reducing the pressure inside the boiler to less than atmospheric. This induces fresh air to enter the furnace.

FEED WATER AND STEAM A small part of the steam and water is passing through the

different components of the system is lost. Therefore, water is added to the feed water system as make up water.

In the boiler drum and tubes water circulates because of the differences in density in the lower and higher temperature section in the boiler. Stem from the drum is further heated in the super heater before it is supplied to the prime mover.

The steam after expansion in the high-pressure turbine is taken to the reheat where it is brought to its original dryness or superheat before being passed on the low-pressure turbine. From the L.P. turbine it is exhausted through the condenser in to the hot well. Steam is being treated in condenser. Condenser extract pump feed the water to the ejectors before supplying it to L.P. heater. Water is then supplied to dearator. Boiler feed pump is being operated for feeding water to drum. From drum water is fed to super heater from where it is being supplied to the turbine.

COOLING WATERA large quantity of the cooling water is required to condense

the steam in the condenser. Cooling water may be taken from the upper side of the river and after passing through the condenser it may be discharged to the lower side of the river. Such a system of the cooling water is practicable if adequate quantity is not available

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water coming out from the condenser may be cooled either in a cooling pond or cooling towers.

ARC QUENCHING PRINCIPLEWhen two current carrying contacts are separated in a

vacuum module, an arc is drawn between them. An intensely hot spot or speaks are created at the instant of contact separation from which metal vapour shoot off, constituting plasma. The amount of the vapour in the plasma is proportional to the rate of the vapour emission from the electrodes, hence to the arc current. With alternating current arc, the current decreases during a portion of the wave and tends to zero. Thereby the rate of the vapour emission tends to zero and the amount of plasma tends to zero.

Soon after natural current zero, the remaining metal vapour condenses and the dielectric strength builds up rapidly, and restricting of the arc is prevented.

The metal vapour arc discharge can only be maintained if a certain minimum current flows. A current that does not attain this level is chopped prior to current zero. This chopping current is kept low in order to prevent unduly high voltage build up when inductive circuits are switched. The use of special contact material ensures that the current chopping is limited to a low value.

The metal vapor plasma is highly conductive and the resulting arc voltage only attains values between 20-200V. For this reason and because of short arcing times, the arc energy developed in the break is very small. This also accounts for the long electrical life expectancy of the vacuum interrupter. Owing to the high vacuum in the interrupter contact clearance of only 6 to 12 mm depending on the rated voltage are needed in order to attain a high dielectric strength.

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SWITCHING OPERATION

When closing command is initiated, the charged closing spring (25) actuates the moving contact (26) through breaker shaft (18), lever (19), insulated coupler (20), and drive link (21).

The forces that occur when the movement of the insulate coupler is converted into vertical motion of the moving contacts are absorbed by the drive link (21) which pivots on the pole support (14) and adapter (22). During closing the tripling spring (23) and the contact pressure spring (24) are charged and latched by a pawl.

The recharging of the closing spring (25) takes place automatically immediately after closing if the supply of the motor is on. Otherwise charging can be done with the help of manual charging handle. In the closed condition the contact pressure springs and the atmospheric pressure, maintains the necessary contact pressure. The contact pressure spring automatically compensates for arc erosion, which is very small.

When a tripping command is given, the pawl releases the energy stored in the tripling and contact pressure springs.

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MODE OF OPERATION

1. CHARGING OF CLOSING SPRING

Motor operated- normally the closing spring is charged by an electrical motor. The motor operated spring mechanism of vacuum circuit breaker is of modular design. It contains separate modules for all the function required for switching operation, as well as for indication and control. Each module can be dismantled and installed easily without it being necessary to carry out any adjustments.

Manually operated- a built in feature also facilitates manual charging of spring if the power supply to motor fails. This is achieved by inserting the hand crank in opening and turning it clockwise until the indicator shows “closing spring charged”.

2. CLOSING OPERATION

After the completion of charging operation of the closing spring, the breaker is ready for closing. If the breaker is to be closed locally, we press the on button. In case of remote operation the closing solenoid unlatches the closing spring.

During closing the tripling spring and the contact pressure springs are charged and latched by a pawl.

3. OPENING OPERATION

If the breaker is to be tripled locally, the spring is released by pressing the “OFF” button. In the case of electrical command being given, the pawl releases the energy stored in the tripling and contact pressure springs. The opening sequence is similar to closing. The residual forces of the tripling spring arrests the moving contact in the open position.

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TRANSFORMERS

The transformer is the most convenient and economical device for transfer of power from one voltage to another voltage at the same frequency. It works on the principle of electromagnetic induction. There is hardly any installation without a transformer. Due to this equipment, it has been possible to transmit bulk power to load centers from far off power houses and to various machineries and switchyards of the power plant. Transformers are of two types: -

Step-up transformer: - Which increases the voltage at secondary side called step-up transformer.

Step-down transformer: - Which decreases the voltage at secondary side called step-down transformer.

MAIN PARTS OF TRANSFORMERS Primary winding Secondary winding Oil tank Drain cock Conservator Breather Tubes for cooling Transformer oil Earth point Explosion vent Temperature gauge Buchholz relay

SOME ACCESSORIES OF TRANSFORMERS ARE DESCRIBED BELOW

1. OIL CONSERVATOR

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Oil conservator is a short of doom mounted on the top of transformer. A level indicator is fixed to it, which gives alarm at low level. Conservator is connected through a pipe to the transformer tank containing oil. This oil expands and contract depending upon the heat produced and so the oil level in conservator is left open to the atmosphere through a breather so that the extra air may go out.

2. BREATHER

The breather is a box containing calcium chloride or silica gel to absorb moisture of oil entering the conservator as it is well known fact that the insulating property of the transformers oil is lost if a small amount of moisture enter in it so dry air is allowed to pass through the breather.

When oil level in oil conservator changes, air goes in & out of the conservator. This action is known as breathing. Dry silica gel is of the blue color. It turns pale pink as it absorbs moisture. The wet silica gel can be regenerated by drying.

3. BUCHHOLZ RELAY

This relay is a gas-actuated relay which is meant for the protecting of oil immersed. Transformer from insulation failure, core heating or any type of internal fault which may cause the heating of oil beyond the specified temperature. Due to any internal fault, oil is heated up & oil vapor so formed causes either the alarm circuit (for less fault) or trip the circuit (for severe fault).

4. EXPLOSION VENT

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It is also a safety device of the transformer which protects the transformer tank from gases induced by & any type of short circuit in the transformer. This consists of a vertical pipe closed by a diaphragm made of thin bakelite sheet. This diaphragm burst or slides out in case of abnormal pressure inside the tank. A diverter plate is used at the bottom of the explosion vent to ensure that gases produce inside the transformer are directed toward the buchholz relay & don’t get collected inside the ventilation and equalize the pressure on each side of the diverter plate.

5. TEMPURATURE INDICATOR

It is also a protective device fitted to the transformer to indicate temperature of transformer oil. For measuring temperature of the oil, bulb of the vapor pressure type thermometer is placed in the hot oil & dial of the thermometer is mounted outside the tank. Two indicating pointers black and red are provided. Alarm contacts are also provided which come into action when predetermined permissible higher temperature is reached under abnormal operating conditions.

6. BUSHING

The bushing serves as supports and insulation of the bus bars and transformer terminal. The bushing consists of porcelain shell body, upper and lower locating washer used for fixing the position of bus bars and mounting flange with the hole drilled for fixing bolt and it is supplied with an earthling bolt.

7. MAGNETIC OIL GAUGE

The magnetic oil level gauge supervises the level of oil in the conservator tank. The oil level gauge is provided on the transformer are of dial type with minimum and maximum level

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marking and a pointer which indicate the level of oil in the conservator. Sometime the scale is also graduated for oil temperature on the basis of its level.

8. TAP CHANGER

The voltage control of transmission and distribution system is obtained by tap changer. Tap changer are either on load or off load tap changer. Tap changer is fitted with the transformer for adjusting secondary voltage.

IMPORTANT TRANSFORMERS IN THE PLANT

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1. GENERATOR TRANSFORMER

It converts 15.75KV which is supplied from generator 220KV and supplied it to the bus bar/grid.

2. STATION TRANSFORMER

It converts 220KV which is coming to station from BBMB to 7 KV and fed to station auxiliary.

3. UNIT AUXILLIARY TRANSFORMER

It converts 15.75KV which is supplied from generator to 7KV to fed unit auxiliary.

H.T. AND L.T. MOTORS

H.T. MOTORS

High tension (H.T.) motors are operated at voltages higher than 415V. in thermal power plant these motors are used at 6.6KV. Specification of H.T. motors which are installed in PANIPAT THERMAL POWER PLANT are:-

1. I.D. FAN MOTORS

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It is known as induced draught fan motor. Its function is to discharge the flue gases to atmosphere through the chimney after passing through the precipitator.

KW VOLTAGE STATOR CURRENT

P.F. WEIGHT RPM

1800 6.6KV 97A 0.89 14300Kg 747

Made by B.H.E.L. (Bharat Heavy Electrical Limited)Star connected.

2. F.D. FAN MOTORS

It is known as forced draught fan motor. Its function is to supply fresh air to the furnace for the burning of coal inside the furnace.


P.F. WEIGHT RPM

790 6.6KV 86A 0.85 ------- 1487


3. P.A. FAN MOTORS

It is known as primary air fan motor. Its function is to carry pulverized coal from coal mill to the furnace for combustion. It creates a strong draught of air that carries the pulverized coal.


P.F. RPM WEIGHT

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1550 6.6KV 156A 0.9 1493 6000Kg


4. COAL MILL MOTOR

It is double squirrel cage motor. Its function is to grind the coal pieces into pulverized coal.


P.F. RPM WEIGHT

2400 6.6KV 264A 0.83 1486 10600Kg


5. C.E.P. MOTOR

It is known as condensate extract pump motor. Its main function is to extract the condensate water to the dearator through heater and economizer.


P.F. WEIGHT RPM

325 6.6KV 35.5A 0.85 3650Kg 1485


6. B.F.P. MOTOR

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It is known as boiler feed pump motor. Its function is to feed the water to boiler drum. It takes water from the deaireater by creating a strong suction. It is the biggest motor of the plant.


P.F. WEIGHT RPM

4600 6.6KV 466A 0.89 14200Kg 1493


7. C.W. PUMP MOTOR

It is known as cooling water pump motor. Its function is to circulate the cooling water to all auxiliaries in the power plant which require cooled water.


P.F. WEIGHT RPM

1800 6.6KV 200A 0.82 19500Kg 498


8. CRUSHER

It is the motor whose main function is to convert the coal into small pieces (50-60mm) and then the coal goes to coal mill.


P.F. WEIGHT RPM

550 6.6KV 58A 0.89 737Kg 740

Made by B.H.E.L. (Bharat Heavy Electrical Limited)

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Star connected.

L.T. MOTORLow tension motors are those which are of 415V. They are used in H.T. motor auxiliary.

1. B.C.W. MOTOR

It pumps the B.C. water to the sump.

KW RATED CURRENT

FREQUENCY RPM

136 43A 50HZ 987

Made by KRILOSKERStar connected.

2. SEAL WATER PUMP MOTOR

It provides a layer of water to the lower position of boiler in order to seal it from the entry of atmospheric air.

KW RATED CURRENT

FREQUENCY RPM

25 43A 50HZ 1479

Made by N.G.E.F.Star connected.

3. SEAL WATER VAPOUR EXHAUST FAN

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It prevents the entry of air bubbles in the turbine cylinder by providing the opposite push.

KW RATED CURRENT

FREQUENCY RPM

1.5 3.1 50HZ 6205


4. CENTRIFUGE PUMP MOTOR

To centrifuges the vapor that enters by change in turbine and remove them.

KW RATED CURRENT

FREQUENCY RPM

7.5 14.2 50HZ 1440

Made by Crompton GreavesStar connected.

5. ASH SULLARY PUMP MOTOR

To pump ash scullery to the ash disposal area.

KW RATED CURRENT

FREQUENCY RPM

100 17.6 50HZ 1485

Made by N.G.E.F.Star connected.

6. EMERGENCY OIL PUMP

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To provide oil to the shaft and bearing of the turbine if seal oil pump and taking oil pump fails.

KW RATED CURRENT

FREQUENCY RPM

15 12.5 NA(DC) -----

7. RAW WATER PUMP MOTOR

It is used to pump raw water from the lake to the plant.

KW RATED CURRENT

FREQUENCY RPM

90 154A 50HZ 1450


8. BEARING COOLING WATER PUMP MOTOR

It supplies cooling water to the motor and other auxiliary for cooling purposes.

KW RATED VOLTAGE

INSULATION POSITION

RPM

335 6.6KV VERTICAL 980


9. AIR COMPRESSOR

This pump is used for compression of air.

Made by Compton Greaves.It is three phase, squirrel cage induction motor running at 1492rpm

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Power: - 400KWStator supply: - 6.6KV, 43A, star connected

Apart from these motors few other important H.T. Machines are installed in a thermal plant site. The few most important of those are station transformer, high pressure ash pump motors.

SWITCHYARD COMPONENTSSWITCH GEAR

Switch gear is a control switch that controls the operation of a power circuit. The two functions of a switch in power systems are:

i) To permit the transmission lines to be convenient. Put into and taken out of service.

ii) To disable the some plant and lines when these become faulty. To be rapidly and safely isolated by automatic means.

The first of these two can be served relatively simple switches. The second however require circuit breakers which are more robust & capable of breaking the large values of fault power that results in faults on major power system since all plants and lines are liable to develop faults as a result of mechanical damage. Electrical breakdown, errors in operation etc. The simple isolators switch in favor of automatic circuit breakers even for switching function. The whole switchgear assembly consists of two parts.

1. PANEL Panel consists of protective relays, mountings of potential

transformer, current transformer, ammeter, voltmeter, & energy meter. The potential transformer is mounted on the panel. The primary is connected to 11KV & reduce voltage from the secondary is given to energy meter as line voltages & for protective purposes.

PROTECTIVE RELAY

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These are the devices which detect the abnormal conditions in the electrical circuit by measuring the electrical quantities which may change during the fault conditions. Basic quantities which may change during the fault conditions are current, voltage, phase, and frequency. Whenever fault occurs, the relays operate to complete the tripped circuit breaker which results in opening of the circuit breaker. It results in the disconnection of the faulty circuit.

DIFFERENT TYPE OF RELAYSi) Earth fault relayii) Over current relayiii) Differential relayiv) Instantaneous relay

2. TROLLY The trolley consists of current carrying contacts called

electrodes. These are normally engaged but in predetermined conditions. Separate to interrupt the circuit, when the contacts are made.

LIGHTENING ARRESTERA lightening arrester is a device, which proves low

impedence path for the flow of current between the line and earth when the systems voltage increases more than the desire value and regains its original properties of an insulator at normal voltage. It is connected between line and earth at the switch yard near the transformer.

The lighting arresters are extensively used for protection of transformers, switch gears and electrical equipments of over head lines, power houses and sub-station. These are also use to protect the line and equipments from skylighting.

Following are the main type of lighting arresters-

i. HORN GAP LIGHTING ARRESTER

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ii. EXPULSION TYPE LIGHTING ARRESTERiii. OXIDE FILM LIGHTING ARRESTERiv. PELLET LIGHTING ARRESTERv. THYRITE LIGHTING ARRESTER

vi. AUTO VALUE LIGHTING ARRESTER

EXPULSION TYPE LIGHTING ARRESTER

It consist of-i. A tube made of fibre which is very effective gas

evolving materials.ii. An isolating spark gap ( or external series gap )

iii. An intrupting spark gap inside the fibre tube.

During operation arc due to impulse spark inside the fibrous tube causes some fibre material of the tube voltise in form of gas, which is expelled through a vent from the bottom of the tube, thus extinguishing the arc just like in circuit breaker. Since the gases generated have to be expelled, one of the

6.6KV CIRCUIT BREAKER

A circuit breaker is a device which1. Makes or breaks a circuit either manually or by remote

control under normal conditions.2. Breaks a circuit automatically under fault conditions.

Thus a circuit breaker is just a switch that can be operated under normal and abnormal conditions both automatic or manually to perform its operation. A circuit breaker is essential consisting of fixed and moving contacts called electrodes. When a fault occurs on power system, the trip coil of circuit breaker is energized which pulls apart moving contacts thus open the circuit. DC supply is

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used for the operation of circuit breaker on the basis of medium used for extinction in the circuit breaker are classified as:

1. Oil circuit breaker2. Air blast circuit breaker3. Sulpher hexafluoride (SF6) circuit breaker

OIL CIRCUIT BREAKER

It is well known that when a circuit carrying a large current is broken, an arc occurs at that point where the contacts are separate. The arching is specially severe when high voltages are involved and if a short circuit occurs on a high voltage cable which is supplied from large power station. The arc would be powerful to bridge the contacts of the switch and destroy it by burning. The device is employed as an oil breaker. An oil breaker posses the property of always breaking an alternative current at its zero value.

VACCUME CIRCUIT BREAKERS

These are designed to handle all recognized switching duties. The breaker is extremely reliable in service, requires only a minimum of maintenance and has long life expectancy. Moreover, their small size and weight, quiet low vibration levels and the fact that they are not affected by variation in temperature and freedom from fire hazards enable the breakers to be used in locations subject to adverse conditions

DISTRIBUTION SYSTEM

The power generated is distributed to the following stations. Auto transformers 1 & 2 of 132KV each give power to: -

1. Indian Oil Corporation Oil Refinery2. Railways3. Munak4. Safidon

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5. Panipat6. Assandh

220KV is directly supplied to

1. Rohtak2. Narwana3. Nissing4. Karnal5. Sonipat

Outgoing and incoming feeders to: -

1. Sewah-12. Sewah-23. Sewah-34. Sewah-4

220KV SUB-STATIONS

The power houses are very far from the load centers. Thus high voltage transmission lines are required to transmit power house from the source of generation to load centers. In between the power house and the ultimate consumer a number of transformer and switching stations are required. These are known as sub-stations.

BUS BARS

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Bus bar can be defined as a conductor which get supply from a number of sources and is loaded into a number of loading center. The conductor used for the bus bar is called MOOSE conductor. They differ from the line conductors in, only the size and are construction-ally similar. The size of MOOSE conductor is 0.54 square inch.

The current carrying capacity of the MOOSE conductor is 1200A per conductor. But in the switchyard, two conductors are used which double the capacity to 2400A. the conductors used are of ACSR conductor.

The total load on the 220KV switchyard is: -

NARWANA-2 1000AKARNAL 400ANISSING 200AROHTAK 300AAUTO 200ATOTAL 2100A

The generation is sometimes less then the total load. Therefore, to fulfill the demand, P.T.P.S. is connected to the grid through Sewah sub-station. The two stations are connected to each other through 4 parallel lines. Thus, if generation is less by 1100A, the supply is taken from the sub-station with 250A per line. These conductors supply the bus-bars of P.T.P.S.

EFFICIENCY OF THE PLANT

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The overall efficiency of a thermal plant is quiet low and does not exceed 40% and for most of the plant it is around 30%. The main reason behind low efficiency of thermal plants is the poor efficiency of the thermodynamic cycle. Heat is rejected to the condenser and the loss is unavoidable due to thermodynamic reasons. Heat cant be converted into mechanical energy without a drop in temperature. And the steam in the condenser is at the lowest temperature. The efficiency of thermodynamic cycle is about 45%.

Losses occur in boiler, turbine, and generator.The losses in turbine occur due to the friction, leakage,

radiation etc. The condenser performance has a great effect on the turbine heat rate because the back pressure measured at the turbine exhaust affects the heat losses. The turbine efficiency is about 85%.

The losses in the generator include the copper losses, iron losses, and mechanical losses. Modern large size generators have an efficiency of about 98% on full load. The auxiliary power consumption is about 5% of the generator output.

SUPERCRITICAL TECHNOLGY

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Utilities all around the world are engaged in a common goal: -To improve efficiency of thermal power plants and to reduce operating costs.

Improvement in efficiency can be brought about mainly by the following two advancements: -

1. By reducing heat losses.2. By increasing thermodynamic efficiency by using higher

steam pressure and temperature.

When temperature of about 600C and pressure of 300 bars is used, water enters a supercritical phase. In this phase water has properties between those of the liquid and gas. When water is in supercritical stage, it can dissolve a number of organic compounds and gasses. If hydrogen peroxide and liquid oxygen is added, combustion is started. Systems based on this principle are called supercritical systems. This process is economical only in 5th range of 500MW and above. An advantage of supercritical turbine is that low grade fossil fuels can be used for generation of power. Moreover nitrogen dioxide emissions are completely eliminated and sulpher dioxide emissions are reduced.

Thus the plant does not require desulpherization and gentrification equipment. Moreover soot collector is also not needed because complete burning of coal occurs. Creation of supercritical water requires large amount of energy. But the whole process can still be more efficient and economical because cost of processing flue gasses emissions is eliminated and cooling water requirements are also reduced. Present day supercritical technology have an overall efficiency of 40%. However it can well be increased taking other crucial factor in account.

CONCLUSION

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Power generation work being handled by a power plant is more than a work of business. It is helping humanity to achieve its need. All around development will come to a stand still if power shortage comes in effect.

Power has become more than a need; it is perhaps the way of living. Per unit consumption of electricity in India is still low; it indicates the living standard of the nation. Hope we will meet future challenges and make our country a better place to live in.

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Documents

Trining Report PTPS,Panipat ( Pardeep Malik)