Traning Report

52
Project Report Everest Power Pvt. Ltd . (100 MW) Hydro-electric Power Project Malana-2 Kullu , Himachal Pradesh

Transcript of Traning Report

Page 1: Traning Report

Project ReportEverest Power Pvt. Ltd .

(100 MW) Hydro-electric Power ProjectMalana-2 Kullu ,Himachal Pradesh

Page 2: Traning Report

ACKNOWLEDGMENT

We are very grateful to our H.O.D. Keshav Attri for providing us an environment to complete our project successfully. We express our deepest gratitude to for his invaluable guidance and blessings. We are very grateful to our internal guide Er. Rambabu , for being instrumental in the completion of our Training with his complete guidance. Finally, we take this opportunity to extend our deep appreciation to our family and friends, for all that they meant to us during the crucial times of the completion of our project.

Page 3: Traning Report

Table of Content

Introduction General layout Essential components of hep Technical feature of Malana 2 Overview of the power house

description of the power house Components of power house: Generator Governor Transformer Runner chamber Switchyard Scada & automation system Protection system

Page 4: Traning Report

INTRODUCTION

The Fitwell Power Projects Private Limited (FPPPL ) is a private sector enterprise. Malana hydroelectric project-2 (2×50MW) is one of its hydroelectric projects in India undertaken for Erection, Commissioning and Testing of various electric equipments from transformers to generators. The Shimla based Everest Power Pvt. Ltd proposes to take up the development of the 2x50 mw Malana-II hydro-electric project in Kullu district of Himachal Pradesh at an outlay of Rs 4900 crore.The Malana – II Hydro Electric Power Project is a Run-of-the-river Hydro Power project, located in the Malana Nallah, a tributary of Parbati River in the Beas Basin, near the Malana village of Kullu District, State of Himachal Pradesh, India. This Project envisages an exploitation of hydro power potential in the upper reaches of Malana Nallah, to produce environment friendly power with Run-of-the-riv er technology to be feed up in the Northern Regional Grid of India. Malana – II HEP is essentially a peaking station utilizing the flow of Malana Nallah to harness about 590 m drop in the riverbed available around 3 km upstream of Malana village. The proposed project will envisage to a concrete gravity dam of only 45 m height above the river bed, across the Malana Nallah with 2 numbers of breast wall type Spillway bays of size 4 m x 5 m to spill down the design flood of the order of 650 cumecs. The water will be diverted through a 5.13 km long power tunnel on left bank, with an under ground Power House. The discharge from Power house will be discharged back into Malana Nallah by a 0.415 km long Tail Race Tunnel (TRT). The Malana-II hydroelectric project is proposed to generate (2 x 50) 100 MW of power, with an energy generation of 428 GWh at 90% dependable year. Due to the construction of the above mentioned dam, which will serve as diurnal storage (storage capacity of 4 hrs) of about 0.2875 Million cum, which will provide a power draft of 18.65 cumecs for peaking. Due to the live storage, an increase in submergence of 3.5 hector will be occurred.

Malana Nallah originates at about EL+ 6200 m from Dudhan Glacier in the Pir Panjal range of Greater Himalaya. It is joined by several nallah and glaciers on it course. The catchment area of Malana Nallah is about 158 Sq Km. Out of the total catchment area 76.2 Sq. Km is under glacier / above permanent snow line. The shape of the catchment area is elongated leaf shaped and the Nallah course is parallel to course of Parbati River. Malana Nallah is a major tributary of Parbati River and it catchment adjoins catchment of Tosh Nallah, which is also a tributary of Parbati River.

The main component of the project comprises a concrete gravity dam of 45 m high. A, 3 m dia and 100 m long, intake from the non overflow section of the dam to Desilting Basin. A surface Desilting Tank, of size 8 m x 6 m and 130 m long, design to exclude silt particulates down to 0.2 mm size. A, 3 m x 2.75 m, D shaped 4.847 Km long, Head Race Tunnel (HRT) on the left bank of Malana Nallah, designed to carry 20 cumecs discharge at 2.75 m/sec velocity. An underground surge shaft with 6 m dia and 90 m deep, at the end of HRT; a Valve chamber, of size 6 m x 10 m x 10 m, located between the Surge Shaft and the Pressure Shaft for emergency closure of flow. A single Pressure Shaft, 2.5 m dia and 666 m long, designed to carry 20 cumecs discharge into the Power House. An underground Power House, of size 20.25

Page 5: Traning Report

m wide 68 m long and 31 m high on left bank of the Malana Nallah, houses 2 nos. of Vertical Axis Pelton wheel driven generating units of 50 MW each, with an energy generation capacity of 428 GWh at 90% dependable year.

Contribution towards Sustainable Development: The Project falls in one of the economically underdeveloped regions of the country. The proposed HEP will bring in substantive economical activities, which in turn lead to development of infrastructures, livelihood generation, provision of basic civic amenities to the villagers around the Project activity, hence, will improve the status of living standards of the villagers. The direct beneficiaries of this project (apart from the project proponent) shall be the villagers of Malana village, which is a small village of about 500 families situated on a plateau of Chandrakhani mountain at a height of about 12000 ft. It is surrounded by the lush-green forests, rugged mountainous ranges and difficult tract not easy to climb. This village can only be approached through three difficult tracking routes, which is through steep terrains. There is no such road connected to the village from the mainland, preventing any sort of business and development activities. The main occupation of the villagers is cultivation but the produced is not enough to suffice the needs of the inhabitants, thus cattle rearing and collection of medicinal herbs are the other sources of livelihood.Social & Economical Wellbeing: The proposed Project will be employed around 800 people during the construction stage and 100 people during the operation stage. Most of the labour forces, except the very skilled and technical labour, will be comprises from the people from the local area, which will support the requirement of employment generation and help in rural poverty alleviation in the region. The Project activities and its auxiliaries around the project area will be able to develop various alternative livelihoods for the villagers, helping them to improve their standard of living. The project will facilitate development ofcommunication and infrastructure like Road, Telecommunication, Post-office, Medical Camp, Training centres etc. in the area, which will improve the economical index and help in livelihood generation. The power generation from the project activity will be used by the State / Region, to enhance the access of power to the remote villages like Malana, help in developing small / cottage industries and stop rural to urban migration. The power will also be utilized at the mechanization of the farming activities through irrigation and other means; will help in getting higher yields by the farmers. This project conserving conventional resources like coal/gas/oil and promoting non-renewable primary natural resources, reduces dependency on imported petroleum and thus addressing the energy security of India.

Page 6: Traning Report

GENERAL LAYOUT

Page 7: Traning Report

ESSENTIAL COMPONENTS OF HYDRO ELECTRIC SCHEMES

Storage ReservoirIt is an essential component of storage based hydro electric schemes. Water available from the catchments area is stored in reservoir during monsoon period so that it can be utilized to run the turbine for generating electric power according to the requirements during lean flow period.

DamDams are the civil structures built across the rivers for intercepting storage of water and also to create head. These are also an important feature of storage based hydroelectric schemes. Run of River schemes normally have Weirs for diversion of river water.

Water Conductor SystemIt is the sytem through which water is carried from the dam to power house. It may consist of tunnels, canals, forebays, pressure shafts/penstocks, surge tank and inlet valves etc.

Power HousePower House is a building housing the turbines, generator, control and protection equipments etc.including auxiliaries for operating the machines.

Tail RaceTail race carries the water discharged from the turbine to a suitable point where it can be safely disposed off into the river in case of conventional hydro schemes. In case of a pumped storage scheme, it carries water to tail pool or water reservoir to be pumped back in to the upper reservoir.

Page 8: Traning Report

Technical Features: of malana-2 Hydro-Electric project.

Dam : Concrete Gravity, 45 m high from deepest foundation level Head Race Tunnel :  3.8 m dia , 4.8 Km long, D shaped Pressure Shaft/Penstock :  2.5 m dia each 801 m long surge shaft :6m dia , height 90m ,circular shape Power house : Underground Type of Turbine : Pelton Net Rated Head  : 603 m Tail Race Tunnel : 3.1m diam , 365 m long, , d shaped

Power generation 2 * 50MW = 100MW.

Calculation Of Hydro Power

Before embarking on any hydro power generation project it is essential to survey the proposed site to calculate the amount of available hydro power The two vital factors to consider are the flow and the head of the stream or river. The flow is the volume of water which can be captured and re-directed to turn the turbine generator, and the head is the distance the water will fall on its way to the generator. The larger the flow - i.e. the more water there is, and the higher the head - i.e. the higher the distance the water falls - the more energy is available for conversion to electricity. Double the flow and double the power, double the head and double the power again.The key equation to remember is the following: Power = Head * Flow * Gravity * efficiency

where power is measured in Watts, head in metres, flow in litres per second, and acceleration due to gravity in metres per second and efficacy in %.The acceleration due to gravity is approximately 9.81 metres per second per second - i.e. each second an object is falling, its speed increases by 9.81 metres per second (until it hits its terminal velocity).

Therefore it is very simple to calculate how much hydro power you can generate.Let's say for example that you have a flow of 20 litres per second with a head of 12 metres. Put those figures in the equation and you will see that:

9.81 * 603*18.92 * 91.4 = 102 MW

Page 9: Traning Report

OVERVIEW OF THE POWERHOUSE

MAT

SERVICE

CONTROL FLOOR

TURBINE/ GENERATOR FLOOR

RUNNER/ MIV FLOOR

Page 10: Traning Report

DESCRIPTION OF THE POWER HOUSE

MAT - Main access tunnel. -Length 279mts.

Service bay - Excitation transformer. - Unit control board. - Common control board. - Dome cover. - Service station board. - Overhead crane. - Dam control panel. - Fire pump control panel. - Microprocessor based protective relay panel

Control floor - neutral grounding transformer. - battery room. - UAT( unit auxiliary transformer). - UAB(unit auxiliary board). - PLC governor panel. - PT& SP cubicle.

Turbine / generator floor - MIV OPU(oil pressure unit). - Spherical valve control panel. - Deep well turbine pumps .

MIV/Runner floor - Runner. - MIV.

Page 11: Traning Report

COMPONENT OF POWER HOUSE Penstock Miv Turbine Governor Generator Bus-duct Protection system Remote system

Page 12: Traning Report

MIV (Main Inlet Valve)

It is used to stop the flow water and contact between penstock and turbine.Type of MIV

Butterfly valve (used for low head below 200m)

Spherical valve (used for high head above 200m)

To operate the MIV of MALANA 2 hep follwwing sequence of events occur.First of all maintain the pressure oil pressure unit is up to 40 Mpa .when the rise up to 42mpa the compressor automatically shut down..

SPHERICAL VALVE OPENING SEQUENCE

SERVOMOTOR LOCK OPENED/MAINTAINANCE SEAL

OPENEDPRESSURE BOTH SIDE

EQUAL?NO

OPEN BYPASS

PRESSURE EQUAL

WORKING SEAL OPENED

SPHERICAL VALVE OPEN

CLOSE BYPASS VALVE

YES

Page 13: Traning Report

GENERATOR

In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. The reverse conversion of electrical energy into mechanical energy is done by a motor; motors and generators have many similarities. A generator forces electrons in the windings to flow through the external electrical circuit. It is somewhat analogous to a water pump, which creates a flow of water but does not create the water inside. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air or any other source of mechanical energy.

MAIN COMPONENTS OF GENERATOR

SUPPORT BRACKETS STATOR ROTOR WITH SHAFT EXCITER AND SLIP RINGS COOLERS & VENTILATION BEARINGS (THRUST & GUIDE ) LUBRICATION SYSTEMS BRAKING & JACKING

HYDRAULIC GENERATOR SET

HYDRAULIC MODEL GENERATOR MODELRated power-51020kW Rated capacity-55555.6kVARated head-603m Rated voltage-11000VRated flow-9.46m3/s Rated current-2915.9ARated speed – 428.6r/s Stator connection-YRunaway speed-746r/m Rated excitationvoltage-190V

Rated excitation current-875A

Rated power factor-0.9Insulation –class F

Page 14: Traning Report

GENERATOR

SPEED

THE MACHINE SPEED DICTATES THE NUMBER OF POLES (P )AS DERIVED BY THE FOLLOWING EQUATION :NS = 120 f/ PP = NUMBER OF POLESNS = SPEED (RPM)f = FREQUENCY (Hz)

EXCITATION SYSTEM - COMPONENTS

EXCITATION TRANSFORMER (DRY TYPE )RECTIFIER SYSTEMAUTOMATIC VOLTAGE REGULATOR FIELD FLASHING UNITSFIELD CIRCUIT BREAKERDISCHARGE RESISTOR

Excitation of rotor windingAn electric generator or electric motor that uses field coils rather than permanent magnets will require a current flow to be present in the field coils for the device to be able to work. If the field coils are not powered, the rotor in a generator can spin without producing any usable electrical energy, while the rotor of a motor may not spin at all. Very large power station generators often utilize a separate smaller generator to excite the field coils of the larger.In the event of a severe widespread power outage where islanding of power stations has occurred, the stations may need to perform a black start to excite the fields of their largest generators, in order to restore customer power service.

Page 15: Traning Report

At the beginning when there is no generation, excitation is provided by supply from battery bank called field flushing.

After 10 seconds when 10% of rated voltage is generated battery bank supply is automatically cut off.

Now excitation is provided using excitation transformer (step down from 11kV to 360kV) , then to 190V using scr panel.

Excitation transformer specification: Type –cast resin dry type.

Governor Governors serve three basic purposes: Maintain a speed selected by the operator which is within the range of the governor. Prevent over-speed which may cause machine damage. Limit both high and low speeds. Generally governors are used to maintain a fixed speed not readily adjustable by the

operator or to maintain a speed selected by means of a nozzle opening or closing. In either case, the governor protects against overspeeding

TYPES OF GOVERNORS:Governors are usually of the following types:

Air-vane (pneumatic) Mechanical (centrifugal)

How does it work?If the load is removed on a machine, the governor immediately closes the nozzle.If the machine load is increased, the nozzle will be opened to prevent Machine speed form being reduced.

Page 16: Traning Report

Functional DescriptionCPU MODULE

Block Diagram

Grid FrequencyUnit SpeedNozzle Servomotor PositionSignal from SSGNozzle Increase/Decrease from Remote/Local.Emergency shutdown from remote/local.Deflector Cut On/Cut Off from remote.Start/Stop from Remote.132 KV Circuit Breaker.Inputs

Page 17: Traning Report

Hydraulic System

Consists of an Oil Pressure Unit, 4 Nozzles & 4 Deflectors.Opening & Closing of these nozzles are controlled by 4 distributing valves connected to a stepper motor(auto operation) & electromagnetic valve(local control) .4 Deflectors are controlled by 1 solenoid , but operate through separate servomotors.

I/O Module

Page 18: Traning Report

Features of Pulse generator/Orientation ModuleSupplies prescribed quantity of pulses(50 in this case) to Stepper Motor Drivers.Direction of rotation of stepper motor is decided by this module.Input supply 24 Volts.

Controlling of Stepper Motor

I/O ModuleInput

Distributing valve for nozzle open/Close

Pulse Generator/Orientation Module

Page 19: Traning Report
Page 20: Traning Report

HuntingHunting is a condition where by the engine speed fluctuate or is erratic usually when first started. The engine speeds up and slows down over and over as the governor tries to regulate the engine speed.This is usually caused by an improperly adjusted carburetor. StabilityStability is the ability to maintain a desired Machine speed without fluctuating.Instability results in hunting or oscillating due to over correction.Excessive stability results in a dead-beat governor or one that does not correct sufficiently for load changesThe governor must have stability and sensitivity in order to regulate speeds properly. This will prevent hunting or erratic engine speed changes depending upon load changes.

Pressure Vessel

ANALOG TO DIGITAL CONVERTOR

Volume- 1600 LRated Pressure-4.0 Mpa

Motors-11KWPump Discharge-1.4L/S

Page 21: Traning Report

BRAKING AND JACKING SYSTEM Jacking (using oil) is used for the purpose of lifting the turbine. Braking (using water) is used for stopping rotor shaft.

Transformer

A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core, and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF) or "voltage" in the secondary winding. This effect is called mutual induction.If a load is connected to the secondary, an electric current will flow in the secondary winding and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (VS) is in proportion to the primary voltage (VP), and is given by the ratio of the number of turns in the secondary (NS) to the number of turns in the primary (NP) as follows:

By appropriate selection of the ratio of turns, a transformer thus allows an alternating current (AC) voltage to be "stepped up" by making NS greater than NP, or "stepped down" by making NS less than NP.

Transformers are essential for high voltage power transmission, which makes long distance transmission economically practical.

Page 22: Traning Report

Transformer used in Malana 2 hep

Generator transformer Excitation transformer Unit auxiliary transformer Station auxiliary transformer Service station transformer Lighting transformer

Generator transformerGenerator transformer is a step up type of transformer. Type of connection of generator transformer is 3 phase, i.e star to delta .Input of generator transformer is star connected and output is delta connected.It convert 11kv to 132 kv then we transfer it to long distance transmition line.Technical specification of generator transformer

Rated power 63900 KVA

Rated voltage 132 HV11 LV

Rated Line Current 279.5 A HV3353.9A LV

Type of cooling ODWF

Frequency 50HzNo of phase 3Insulation class FType of Connection Star to delta

Parts of GT Heat exchanger Buchholz relay Breather Flow meter Pressure gauge Flow well centrifugal Oil pump

Excitation transformerExcitation transformer is used to give dc supply to the rotar of generator. This creates magnetic flied b/w stator and rotor. When the rotor rotates it cuts the magnetic field and electricity produce Acc. to faraday law of induction.Rated capacity 630 KVARated excitation voltage 190 VRated excitation current 875 ARated power factor 0.9 laggingInsulation class FFrequency 50 HZCooling method AN

Lighting transformer

Page 23: Traning Report

It is simple step down transformer , which is used in power house for lighting purpose.The detail of lighting transformer is shown below……….Input voltage 415Output voltage 415Phase 3 phaseCapacity 125kvaFreq. 50Hz temp. rising

Unit auxiliary transformerThe unit system for voltage step up is adopted universally which each generator is directly connected to the unit step up transformer. A generator and its unit step up transformer form the unit. Each unit has its own turbine, control panel and auxiliaries. The unit auxiliaries are supplied through unit auxiliary transformer.

Capacity 500kvaVoltage 433vCurrent 666.69APhase 3Type of cooling ANFreq. 50hz

Station auxiliary transformerThe station auxiliaries are supplied through another transformer called station service transformer. A general connection diagram of a unit step up transformer. The unit system for voltage set up is available for large hydro power plant.Capacity 1mvaVoltage VCurrentPhase 3Type of cooling ANFreq. 50hz

Service station transformerService station transformer is used to step down the voltage 132kv to 11kv . It is it is 3 phase transformer. Connection are star to star type.Output of S.S.T. is used ot give supply to

Company guest house Dam side Over all lighting And one is spare

Capacity 5000kvaVoltage 132/11 vCurrent 21.87/262.43Type of cooling AFONPhase 3Connection Star to star

Coolant used in transformer

Page 24: Traning Report

High temperatures will damage the winding insulation. Small transformers do not generate significant heat and are cooled by air circulation and radiation of heat. Power transformers rated up to several hundred kVA can be adequately cooled by natural convective air-cooling, sometimes assisted by fans. In larger transformers, part of the design problem is removal of heat. Some power transformers are immersed in transformer oil that both cools and insulates the windings. The oil is a highly refined mineral oil that remains stable at transformer operating temperature. Indoor liquid-filled transformers are required by building regulations in many jurisdictions to use a non-flammable liquid, or to be located in fire-resistant rooms. Air-cooled dry transformers are preferred for indoor applications even at capacity ratings where oil-cooled construction would be more economical, because their cost is offset by the reduced building construction cost.The oil-filled tank often has radiators through which the oil circulates by natural convection; some large transformers employ forced circulation of the oil by electric pumps, aided by external fans or water-cooled heat exchangers. Oil-filled transformers undergo prolonged drying processes to ensure that the transformer is completely free of water vapor before the cooling oil is introduced. This helps prevent electrical breakdown under load. Oil-filled transformers may be equipped with Buchholz relays, which detect gas evolved during internal arcing and rapidly de-energize the transformer to avert catastrophic failure. Oil-filed transformers may fail, rupture, and burn, causing power outages and losses. Installations of oil-filled transformers usually includes fire protection measures such as walls, oil containment, and fire-suppression sprinkler systems.

Runner chamber

TurbineTurbine is a device which is used to convert mechanical energy(kinetic energy of water) into electrical energy.

Types of turbine …..There are two types of turbines….Impulse turbine Reaction turbine

Impulse turbine :–

Page 25: Traning Report

Pelton wheel Efficiency (ἠ) – 91%Head for pelton turbine – 300 to 600 mReaction -turbine :-Kaplan turbine-Efficiency (ἠ) – %Head for kaplan turbine – 0 to 60 m

Francis turbine –Efficiency (ἠ) – %Head for francis turbine – 30 to 350 m

In malana -2 we are using pelton wheel turbineAs the head is 603 meter and the efficiency is 91.4%Weight of the runner of turbine is about 8 tonnes.Dia of turbine –Number of blades on runner-21

Nozzles

Nozzle is a hydraulic device which is used to increase or decrease the velocity of water by opening or closing the valve which is controlled by governer. In Malana -2 we are using 4 nozzles in one unit for rotating the runnerThese nozzles are operated with the help of governer . By this we are able to control the speed of runner..

Deflectors

Page 26: Traning Report

Deflector is device which is used to deflect the flow of water coming from the nozzles to stop the runner. Our runner takes 2 sec to open and 2 sec to close. By this we are able to stop the turbine slowely.Breaking jetBreaking jet is a device which is used to stop the runner quickly, when the flow of water is to be stopped or deflected from the nozzles , the runner keep on moving because of inertia . To stop the runner quickly an opposite jet or stream of water is blown on the runner , to stop it known as breaking jet . Breaking jet is come into play when the speed of turbine is is reached at 5% to its original speed…

Specification of the various components machine

Type of turbine- PELTON. Weight of the rotor- 118 tonne. Weight of the stator- 50 tonne. Weight of the runner- 8 tonne. Weight of the nozzle- 4.5 tonne. Weight of the MIV- 37 tonne. Weight of the counter weight- 10 tonne( each). Weight of the lever arm- 2.5 tonne (each). Internal diameter of the MIV- 1300mm. Rated speed 428r.p.mm

No. of stator poles-14.

Page 27: Traning Report

BEARINGS

schematic diagram showing positions of guide bearings

Page 28: Traning Report

FUNCTIONS OF BEARINGS To suppress the vibration produced during rotation of rotor bearings are used shaft . It holds the shaft steadily. They are dipped in oil to provide spacing between rotor and bearings. Thus prevent

them from rubbing against each other. Deep well water pumps are used to supply water from sump for cooling this oil.

Heat exchangers are placed in TRT( tail race tunnel) for the purpose of exchanging heat.

Four bearings are used namely: Thrust bearing at the top. Then upper guide bearing. Lower guide bearing. Turbine bearing. To suppress the vibration produced during rotation of rotor

bearings are used shaft . It holds the shaft steadily. They are dipped in oil to provide spacing between rotor and bearings. Thus prevent

them from rubbing against each other. Deep well water pumps are used to supply water from sump for cooling this oil. Heat exchangers are placed in TRT( tail race tunnel) for the purpose of exchanging

heat. Four bearings are used namely: Thrust bearing at the top. Then upper guide bearing. Lower guide bearing. Turbine bearing.

Page 29: Traning Report

SWITCHYARDPurpose

Transmit the electricity generated up to the load centre. Proper control and protection. Communication. Exchange of power in emergency

Page 30: Traning Report

SINGLE LINE DIAGRAM OF SWITCHYARD

DESCRIPTION OF THE DIAGRAM

L.A

P.T/

W.

ISO

C.T

C.B

ISO

ISO

C.B

C.T

ISO

L.A

G.

G

BUS BAR

T.

Page 31: Traning Report

L.A- Lightning arrestor Lightning arrestors are used to protect the equipment from over voltages

caused by lightning . The substation equipment has also to be protected against traveling waves due

to lightning strokes on the line entering the substation

W.T- Web trap It is used for PLCC( power line carrier communication). It prevent high frequency signal from going into the transformer. So

that it can be protected from damage.

C.B- Circuit breaker

Page 32: Traning Report

Basically a circuit breaker is an insulated chamber and comprises a set of fixed & movable contacts. The contacts can be separated by means of an operating mechanism. The separation of current carrying contacts produces an arc. The arc is extinguished by a suitable medium as transformer oil, vacuum, Air, SF6 gas, etc.

Depending upon the arc extinguishing method circuit breakers are different types as: Depending upon the arc extinguishing method circuit breakers are different types as: Minimum oil circuit breaker

2- Vacuum circuit breaker3- Air blast circuit breaker4- SF6 circuit breaker

SF6 circuit breaker is a modern reliable and most commonly used C.B. Sulphar hexaflouride gas is used for extinguishing of arc. It is a heavy non-

flammable, non-toxic and colorless gas with a high electric strength which is about 2.5 times that of air. Electro negativity is the best property of the gas. The gas pressure is to be maintained around 6 to 7 kg/ cm2.

It is a on load switch.

T.E- Telephone exchange - It receive high frequency signal from web trap. - It make use of power transmission lines as telephone lines for communication.

C.V.T- Capacitive voltage transformer- These are used for transforming the voltage to a lower value for the purpose of

Page 33: Traning Report

voltage measurement.-The CVT can also be used for carrier communication and data transmission.-CVTs are generally connected parallel to bus bar for voltage measurement and connected parallel to feeders for carrier communicatoin

ISO- Isolator Isolator is an off load switch which can be used for disconnecting a circuit under no

current condition. The following are the various types of isolators :- Vertical Break Type : Where the moving contact moves in the vertical plane. Horizontal Break Type Where the moving contacts swivel around the insulator stacks to make contact in the

middle.

C.T- Current transformer

Page 34: Traning Report

The current transformers work on the same principle as the power transformers. The primary winding carries the operating current & the secondary winding is used to measure the current component of the circuit

The current transformers work on the same principle as the power transformers. The primary winding carries the operating current & the secondary winding is used to measure the current component of the circuit .

These are used for transforming the current to a lower value for the purpose of measurement, protection .

The outdoor CTs are oil immersed type single phase 50 cycles, self cooled. These are sealed to eliminate breathing and to prevent air and moisture from entering into the tank

Page 35: Traning Report

.

132KV OUTDOOR XLPE TERMINATION

CABLE SPECIFICATIONS Area of crossection 400mm. XLPE(cross linked poly ethylene) used as dielectric. Semiconductor layer used for maintaining uniform voltage distribution. Metallic armor for mechanical strength of cable & for grounding purpose. PVC ( poly vinyl chloride) layer for insulation of cable and keeping it moisture free. Suitable for high voltage.

DRAWING AS PER DESIGN

A=1240mm. B=80mm. C =60mm.

Page 36: Traning Report

D =380mm. E =220mm. F =1980mm.

TERMINATION KIT Copper lug.

Stress cone bracket.

Silica gel. Aluminum foil. HV additive. Lead tape.

Stress cone.

Wiping sleeve

Page 37: Traning Report

Copper sleeve.

Transparent white tape.

PVC tape. DB-50 tape. Lead strip( soldering purpose). Boot (black).

Page 38: Traning Report

PROCEDURE OF CABLE TERMINATION

Cable is heated for 2-2.5 hrs. up to a temperature of 70-800c using resistive heating system. Heating is done to reduce it’s mechanical strength to make it suitable for

further processes.

Now ,PVC layer is removed along with armor up to a length of 1980mm with the help of electric saw.

Now , semiconductor layer (black) is removed with help of glass plate up to same length completely. If semiconductor layer remains then during operation it conducts leakage current & termination kit may blow off.

Now remaining XLPE layer (white) is finely smoothened with help of emery paper as per design requirements.

Now XLPE layer of length 80mm is removed at the top & tapered from 80mm to 140mm.

Now connector lug (copper) is placed at the top.

Page 39: Traning Report

Now wiping sleeve is placed at the bottom of finished portion of XLPE cable.

Now porcelain bushing is cleaned from inside & stress cone bracket is placed inside it

and tightened with nuts & bolts.

Page 40: Traning Report

Now silica gel is applied on the finished portion to press (vertically) down stress cone

( dia. less than finished surface) easily.

In the mean time earth wire is soldered over the periphery of wiping sleeve with help of cutting set.

Now bushing is lowered and HV additive is poured inside it & kit is closed.

Page 41: Traning Report

Now boot (black) is heated with cutting set ( boot take the shape of the object after

heating over which it is placed) and termination is completed.

Page 42: Traning Report

TESTING OF POWER TRANSFORMER

Page 43: Traning Report
Page 44: Traning Report