SUMMER TRAINING

Project Report

On

DRY TYPE TRANSFORMER

SUBMITTED TO PROJECT MANAGER

Mr. Dhruva Bhargav Mr. H.K. Sharma

G.M. (HRD) Sr. Manager

D.T.T & Bay 8

SUBMITTED BY

ASHISH VERMA

DEPARTMENT OF ELECTRICAL ENGINEERING

MAHARANA PRATAP ENGINEERING COLLEGE, KANPUR[2010 – 2011]

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ACKNOWLEDGEMENT

Doing this project was a great experience for me, so I would like to express my gratitude to all those people who helped me during this project.

I am thankful to BHEL Jhansi for giving me the opportunity to do this project. I am thankful to my project guide Mr. H.K. Sharma (Sr. manager D.T.T &Bay 8) and technical staff which has shown a great interest in helping me to understand the functioning of various machineries. I am also thankful to numerous BHEL engineers who helped me in understanding the workings of their respective departments.

I would also like to thank all my fellow trainees who have been a constant source of encouragement and inspiration during my training period. At last I would thank my family for giving their whole hearted support in preparing this project.

ASHISH VERMA

B.TECH third year

(Electrical Engineering)

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CONTENTS

BHEL Jhansi 1

Brief introduction

Manufacturing Unit of BHE 2

Product Profile 3

BHEL Objectives 5

Achievement OF BHEL 12

Rotation Report 14

Dry Type Transformer 23

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BHEL JHANSI

Brief Introduction

By the end of 5 year plan it was envisaged by the planning commission that the demand for

power transformer would rise in coming year. Anticipating the country’s requirement BHEL

decided to set up a new plant, which would manufacture power transformer and other type of

transformer in addition to the capacity available in BHEL Bhopal. The Bhopal plant was

engaged in manufacturing transformer of large rating and Jhansi unit will focus on power

transformer up to 50 KV, 132 KV class & other transformer like instrument transformers,

traction transformer for railway etc.

The unit of Jhansi was established around 14 km from the city on N.H. NO. 26 on Jhansi

Lalitpur road in 1974 with an investigated cost of Rs 16.22Crores inclusive of Rs 2.10Carores

for township. It is called second generation plant of BHEL. Its foundation was laid by late Mrs.

Indira Gandhi on 9 Jan 1974. The commercial production of the unit began with an output of 53

lakes, since than there has been no looking back for BHEL Jhansi.

The plant of BHEL was equipped with the most modern manufacturing, processing and testing

facilities for the manufacturing power, special transformer and instrument transformers, diesel

Locomotives, Ac/Dc locomotives.

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The raw materials that are used for manufacturing goes through lab tests in addition with strict

quality checks at various stages during the production. Up till 1987 BHEL Jhansi was engaged in

manufacturing transformers and than in 1987-88 BHEL progressed a step further by undertaking

the production of the locomotives and subsequently it is manufacturing Ac/Dc locomotives also.

MANUFACTURING UNIT OF BHEL

First Generation Units

BHOPAL Heavy Electrical Plant

HARDWAR Heavy Electrical Equipment Plant

HYDERABAD Heavy Electrical Power Equipment Plant

TIRUCHY High Pressure Boiler Plant

Second Generation Units

JHANSI Transformer and Locomotive Plant

HARDWAR Central Foundry and Forge Plant

TIRUCHY Seamless Steel Tube Plant

Unit Through Acquisition and Merger

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BANGALORE Electronic Division

Electro Porcelain Division

New Manufacturing Units

RANIPAT Boiler Auxiliaries Plant

JAGDISHPUR Insulator Plant

RUDRAPUR Component and Fabrication Plant

BANGALORE Industrial System Group

PRODUCT PROFILE

Products Rating

1. Power Transformer up to 400 KV 315 MVA

2. Rectifier Transformer up to 132 KV 120KVA

3. Furnace Transformer up to 33 KV 60 MVA

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4. Voltage Transformer up to 220 KV

5. Current Transformer up to 400 KV

6. Traction transformer

(a) Single Phase Freight Loco. up to 25 KV 5400 KVA

(b) Three Phase Freight Loco up to 25 KV 7475 KVA

7. Transformer For ACEMU up to 25 KV 1550 KVA

8. Cast Resin Dry type Transformer up to 33 KV 15 MVA

LOCOMOTIVES

1. Diesel Locomotives

2. AC/DC Locomotives

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3. Special purpose wagons

4. Rail cum road vehicle

5. Synchrolift

BHEL OBJECTIVES

A dynamic organization is one which keeps its aim high, adopts itself quickly to changing

environment, so we are in BHEL. The objectives of the company have been redefined in the

corporate plane for 90’s.

Busyness Mission

To maintain a leading position as supplier of quality equipments, system and services in the field

of conversion, transmission, utilization, and conversation of energy for application in the area of

electric power, transportation oil and gas exploration and industries. To utilize company’s

capability and resources to expand busyness in to allied area an priority sector of economy like

defense, communication and electronics.

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Growth

To ensure a steady growth by enhancing the competitive edge of BHEL in existing busyness,

new area and international market so as to fulfill national expectation from BHEL.

Profitability

To ensure a reasonable and adequate return on capital employed, primarily through

improvements in operation, efficiency, capacity utilization & productivity and to generate

adequate internal resources to finance the company’s growth.

Focus

To built a high degree of customer confidence by providing increased value of his money

through international standards of product quality performance and superior customer service.

People Orientation

To enable each employee to achieve his potential, improve his capabilities, understand is role

and responsibilities and participate and contribute to the growth and success of the company.

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Technology

To achieve technological excellence in operation of indigenous technologies and efficient

absorption and adoption of imparted technologies to suit business.

Image

To fulfill the expectations, which stack holders like government as owner employee, customer

and the country at large have from BHEL.

Power

Provides a gamut of equipment for thermal, hydro and nuclear plants. Range includes product

and system for power generation, transmission and utilization.

Highlights

1. Thermal

Maximum size supplied 500 MW with the capability to manufacture 1000 MW units.

Already over 250 sets contracted.

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2. Nuclear

235 MW sets supplied, 500 MW sets under manufacture.

3. Gas

Maximum size supplied 150 MW(ISO), capability to manufacture 240 MW(ISO)

4. Hydro

Maximum size supplied 165 MW, 250 MW units under manufacture.

Major Client

State electricity boards/Power corporations

NTPC

National Hydro Electricity Power Corporation

Nuclear Power Corporation

Damodar Valley Corporation etc.

Transmission

BHEL is manufacturing transmission equipment for all voltage rating including 400 KV class

transformers, switch gears, control and relay panel, insulator, capacitor and other equipment.

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Highlights

1. System

HVDC

Compensator Series and Shunt(SVC)

Substation

Power System analysis

SCADA

2. Products

Transformer (oil type and dry type)

Switch gear (oil, vacuum, & SF medium )

GIS

Capacitor

CT/PT/CVT

Reactor

3. Voltages

AC 400 to 800 KV under development

DC up to 500 KV

Major Clients

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SEV’s

West Bengal power development Corp ltd

Tenughat Viduat Nigam Ltd

NTPC

Rashtriya Ispat Nigam

National Fertilizers Ltd, etc

Industry

Offers a comprehensive range of electrical, electronic and mechanical equipment for a host of

industries like fertilizer, petrochemical, refineries, paper, sugar, rubber, cement, coal, steel,

aluminum and mining.

Highlight

1. Product & system

Turbo set

Diesel generator sets

Boiler

Steam generator

Pump

Seamless steel tube

Drives and controls

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C & I, etc

2. Application

Fertilizer

Petrochemical

Coal

Steel

Aluminum

Mining etc.

Major Clients

National Aluminum Corporation

Hindustan Fertilizers & Chemicals Ltd

Hindustan Paper Corporation

Hindustan sugar, Mysore sugar

Indian Oil Corporation

Defense Ministry

Indian Petro Chemicals Ltd

Reliance Industries, etc.

ACHIVEMENT OF BHEL

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BHEL has

1. Installed equipment for over 90,000 MW of generation fro utilization, captive and

industrial user.

2. Supplied over 2, 25,000 MVA transformer capacity and other equipment operating

and transmission and distribution network AC/dc up to 400 KV (AC/DC).

3. Supplied over 25000 motors with drive control system to power projects,

petrochemicals, refineries, steel, aluminum, fertilizer, cements plants etc.

4. Supplied reaction electrics and AC/DC locos to power over 12000 Kms railway

networks.

5. Supplied over 1million valves to power plants and other industries.

BHEL vision is to become a world class engineering enterprise, committed to enhancing

stakeholder value. The company is striving to give shape to its aspiration and fulfill the

expectations of the country to become a global presence:-

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Vision:

“A world class engineering enterprise committed to enhance stakeholder values.”

Mission

“To be an Indian multinational engineering providing total business solution through quality

product system and services in the field of energy, transportation, industry, infrastructure and

other potential area.

Values

Ensure speed of response.

Foster learning, creativity and team work.

Respect for dignity and potential of individuals

Loyalty and pride in company

Zeal for the change.

Zeal to excel.

Integrity and fairness in all matters.

Strict adherence to commitments.

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ROTATION REPORT

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TRANSFORMER MANUFACTURING

1. Inventory

It is the section of storage of raw material.

2. Fabrication

Fabrication is nothing but production. It comprises of three bays:

Bay 0:

It is basically a machine / preparation shop. This section has following machines:

1. Pacific Hydraulic Shear & pressure: Hydraulically operated machine to cut to sheet of

different thickness. It contain pressure holder which is used to flatten the sheet.

2. CNC (Computerized Numerical control) Flame cutting machine: Used to cut

complicated shaft item using OXY-ACETYLENE flame. Maximum 6 torches are

used in it. Cutting is done on the basis of computer programming.

3. Rolling Machine: used for making cylindrical shape from a sheet.

4. Bending Machine: Hydraulically operated machine used to bend the job.

5. Hydraulic power press: Has the capacity of 100 tons used to flatten the object.

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6. Nibbling Machine: used to do various tasks like straight cutting, circle cutting,

nibbling, slot cutting, circular and square punching.

7. Hydraulic Guillotine Shear: It is to cut the sheet which has maximum cross section

area of (3200*13 sq.mm).

8. Butler machine: used for facing, tapering, & slot cutting.

9. Plasma Cutting Machine: used for non ferrous metal.

Bay 1:

It is an assembly shop where different part of tank comes from bay 0. Hear welding

processes are used for assembly, after which a rough surface is obtained and is

eliminated by grinding. Grinding operates at 1200 RPM.

Bay 2:

It is assembly shop dealing with making different objects like.

Tank Assembly

Tank cover assembly

End frame assembly

Cross feed assembly

Core Clamp assembly

Pin & pad assembly

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Before assembly, short blasting is done on different part of jobs to clean the

surface before painting.

After assembly some tests are done as non-destructive tests like.

1. Ultrasonic Test: To detect the winding fault on CRO. At the fault place high amplitude

waves are obtain.

2. Die Penetration Test: Red solution is put at the welding and then cleaned. After some

time white solution is put. Appearance of red spot indicates a fault at the welding.

3. Magnetic crack detection: magnetic field is created and then iron powder is put on the

welding. Sticking of the iron powder in the welding indicates the fault.

4. X-Ray Test: It is same as human testing and a fault is seen in X-ray.

5. Air / Vacuum Test: the air is filled inside the body of transformer, than soap solution is

produced outside the body. If the holes appear, it is indicate the fault.

Bay 3:

The bay has basically three sections.

Machine Sections: To operation to form small components of power and traction

transformer are done is this section. The shop consists of following machines.

CENTRAL LATHE: It consist one tail stock, head stock. Lower part of tail stock

is fixed and tail stock spindle is moving. On this machine is facing, turning and

threading is done.

TURRET LATHE: Its function is same as central lathe machine but it is used for

mass production. Here turret head is used in presence of tail stock because turret

head contains many tailstocks around six.

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CAPSTAN LATHE: It is belt driven.

RADIAL ARM DRILLING MACHINE: Used for drilling and boring.

HORIZONTAL BORING MACHINE: It is computerized and used for making

bore, facing etc.

MILLING MACHINE:

a) HORIZONTAL MILLING MACHINE: Used for making gear and cutting

operations.

b) VERTICAL MILLING MACHINE: The machine does facing, slot cutting

and T-slot cutting.

COPPER SECTION:

Tube slitting Machine: used for cutting the tube along its length and across the

diameter.

HYDRAULIC SHEARING MACHINE: It is hydraulically operated and its blade

has V-shape and a thickness 15 mm.

WATER COOLED BRAZING MACHINE: It contains two carbon brushes. The

sheet is put along with sulfas sheet and the carbon brushes are heated. A lap joint

is formed between the sheets as the sulfas sheets melts.

LINCING BELT MACHINE: It creates a smooth surface.

SOLDER POT MACHINE: It has a pot that contains solder. Solder has

composition of 60 % Zn and 40 % Pb.

3. TOOLING MACHING: In this section the servicing of tools is done.

Blade sharp machine

Mini surface grinding Machine(used for grinding purpose)

Tool and surface grinding Machine(used to grind the tool)

Drill grinding Machine (to grid the drills)

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Bay 4:It is the winding, coil and moulds section.

TYPES OF WINDING

a) Reverse section winding

b) Helical winding

c) Spiral winding

d) Interleaved winding

e) Half section winding

The type of winding depends upon the job requirement. Also, the width and thickness of conductors designed and decided by design department.

TYPES OF COIL

1. Low voltage coil

2. High voltage coil

3. Tertiary coil

4. Tap coil

THE MOULDS ARE OF FOLLING TYPES

1. Belly type

2. Link type

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3. Cone type

Bay 5:

It is lamination and punching shop. The lamination used in power, dry and ESP transformer etc. for making core is cut in this section. CRGO (cold rolled grain oriented) silicon steel is used for lamination, which is imported in India from Japan, U.K and Germany. It is available in 0.27&0.28 mm.

For the purpose of cutting and punching the core three machines are installed in the shop.

Slitting machine (used to cut CRGO sheets in different width)

CNC cropping line pneumatic

CNC cropping line hydraulic

Bay 6:

Single phase transformer for AC locomotives is assembled in this section. In this bay core winding and all the assembly of testing of traction transformer is done.

The tap changer of rectifier transformer is also assembled in this bay.

Bay 7:

This is the insulation shop. Various type of insulation are:

AWWW: all wood water washed press paper. The paper is 0.2-0.5 mm thick cellulose paper is bound on conductor for insulation.

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Pre-Compressed Board: this is widely used for general insulation and separation of conductors in the form of blocks.

Press Board: this is used for separation of coil e.g. LV from HV. It is up to 38 mm thick. Fiber Glass: this is resin material and is used in fire prone area. Bakelite Gasket: used for protection against leakage. Silicon Rubber Sheet: It is used for dry type transformer.

Machine used for shaping the insulation material are:

1. Cylindrical machine2. Circular cutting machine3. Bending machine4. Punching press machine5. Drilling machine6. Guillotine machine7. Bench saw8. Jig saw9. Circular saw10. Lansing machine

Bay 8:

It is the instrument transformer and ESP transformer manufacturing section.

1. Instrument transformer: used for measuring the AC voltage and currents of high ratings.a) Current transformer: it is a step down transformer. The body is divided in to

three parts – top chamber, bushing, bottom chamber. Top chamber is the cylindrical tank of mild steel. It has terminal for connection of HV coil. It also has oil window to indicate the oil level. Below it is bushing which houses the winding and also act as insulator. It has several folds or rain sheds to provide specific electric field distribution and long leakage path. Some bushings are cylindrical while modern ones are conical, as the amount of oil porcelain used is reduced without any undesirable effects. Bottom chamber houses the secondary winding. There is also a connection box to which the connection of low voltage coil is made.

b) Voltage Transformer: It is also an step down transformer and outer construction is same as that of CT. the difference is only in winding.

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2. ESP Transformer: Electrostatic precipitator transformer is used for environmental applications. It is used to filter suspended charged particles in the chimneys of the industries particularly power plants and cement industries. It is a single phase step up transformer. An AC reactor is connected in series with primary coil. The output must be DC which is obtained by rectifying the AC using bridge rectifier. A radiofrequency choke in connected in series with DC output for the protection of secondary circuit and the filter circuit. The output is choose negative because the particles are the positively charged. The dc output from the secondary is given to the set of plates arrange one after other. Positively charged impurity particles sticks to the plates and are jerked off. For this a network of plates has to be setup all across the plant. This process is very costly in comparison to the transformer cost. A relevant is also provided to prevent the transformer from bursting. If higher pressure develop inside it.

An oil temperature indicator and secondary supply spark detector are also provided. One side of the transformer output is taken and the other side has a marshalling box, which is the control box of the transformer.

Bay 9:

In this bay power transformer are assembled after taken sub assemblies from Bays (0 to 8).

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DRY TYPE TRANSFORMER

The dry type transformers manufactured in BHEL consist of high voltage and low voltage

windings made up of copper conductors which are completely encapsulated and cost under

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vacuum. The casting is done using liquid epoxy resin, rain forced by fiber glass insulation of

class F to form a very robust and very maintenance free insulation system for winding. The HV

or LV coils are cast separately to form individual solid cylinder.

The core is made from lamination of CRGOS. The core edges are coats with special resin as

protection against rusting.

The transformers are provided with suitable protective steel enclosures. The enclosure are

provided with louvers covered with wire mesh to allow free circulation of clean natural air inside

the enclosure of air natural cooling.

For thermal protection, RTD PT-100 sensors are embedded in the coils to do the temperature

monitoring of the transformer. These sensors feed signal to the temperature scanner unit for

continuous monitoring of winding.

The temperature scanning unit is provided with auxiliary relays, one for alarm and one for trip.

Alarm relay should be wired with suitably located alarm to give an indication if transformer

winding temperature is exceeded. The trip relay should be wired with HT circuit breaker to trip

the supply in case the temperature rises beyond the safe limit because of any fault which may

damage the transformer permanently. The control wiring is terminated on the terminal blocks

located inside the junction box on the enclosure. The HT and LT side are terminated suitably for

the connections of the cables. A separate earthing flat from LV neutral is brought out for the

provision of system earthing. In addition of the enclosures is provided with suitable earthing

pads for body earthing.

MANUFACTURING PROCESS

The dry cast iron resin transformers are manufactured using copper conductors for winding and

glass & epoxy resin for insulation. The process is as follows:

1. WINDING: Copper conductors make both LV and HV winding over steel formers.

The winding are densely embedded in glass fibers and are tightly by glass tapes. LV

windings are generally helical in shape and HV winding are made spiral or disk type.

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Both the windings are made separately except for very small rating where HV and LV are

made together because of small diameter.

After the winding is complete the bound coils are placed in separate steel moulds and are

pre dried in heating oven or heated vacuum chamber before casting.

2. CASTING: Dried moulds containing in vacuum chamber for casting. Casting is done

by utilizing the unique properties offered by pure liquid epoxy system. Various

constituents of epoxy resin are first heated in separate vacuum post to eliminate dissolved

gases and moisture. Then these are mixed in precise proportion as per the requirements

and supplied to dried windings placed inside moulds under high vacuum to give void

less embedment of winding by epoxy. The epoxy is slowly absorbed by the fiberglass

reinforcement provided during winding to from a dense fibrous mass. When the moulds

filled by liquid epoxy ensuring complete void less encapsulation they are taken further

for processing in post curing ovens. The whole process control by computer carried out

automatically as high degree of accuracy is required.

The epoxy reinforced by the glass, after curing form a solid dense mass, which

encapsulated the copper winding. The process gives the winding better mechanical

strength than any other form of manufacturing process and at the same time epoxy system

employed provides the high dielectric strength.

3. CUTTING AND DRESSING: After the coils are cured they are taken out of

moulds. The cured and dry coils are hard enough to carry out any matching. Rather the

hardness of fiber glass reinforced epoxy resin cast coil require special tools and blades

and for matching as ordinary steel tools used for cutting steel and other metals wears out

quickly.

Excess epoxy deposited on the top of coil is swan of to require dimension and sharpen

edges are removed and smoothened by milling or grinding. Touching up paints is applied

to coil if required and finished coils are tested and send to assembly.

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4. ASSEMBLY OF TRANSFORMER: The finished cast resin coils are placed in

core by removing the top yoke of pre-assembled core. The top yoke is replaced after

pacing HV and LV coils. The coils are supported at the top and bottom by end blocks.

The coil and windings are then clamp and tightly together by galvanized steel channels

and terminal gear assembly is carried out for the required HV and LV terminations.

Special class F resin is applied on the exposed area of core as a protection against rusting.

The core and coil assembly is then mounted on the roller base. After fixing bidirectional

rollers, the core and coil assembly along with roller is placed inside the enclosures. The

enclosures are bolted to core and assembly. Necessary winding is carried out and all the

fittings and accessories are mounted on the transformer.

The finished transformer is now ready for testing and maintenance free service.

CHARECTERSTICS & FEATURES

1. MAINTENANCE FREE NATURE OF COST RESIN DTT: These are

virtually maintenance free under most severe topical, dusty and corrosive

environment.

No drying of transformer required after duration of shut down as epoxy cast coil are

non hygroscopic and do not absorb moisture. Infect experiments has shown that

transformer continue to work at rated voltages even with coils sprayed with water.

This eliminates the need of readjustment and retensioning of windings in DTT.

Similarly no control and checking of oil are required. This leads to considerable

savings in expenditure required for maintenance and periodic recalculation of oil.

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2. IMMEDIAT SWITCH ON: Because of non hygroscopic insulation system the

transformer can be switched on without pre-drying even after long periods of shut

down.

3. SELF EXTINGUISHING AND INFLAMMABLE: The insulation system

of fiber epoxy provides transformer coil with self extinguishing properties. This is

most important properties of cast resin transformer and makes possible their use in

indoor condition.

4. IMPULSE STRENGTH: The winding are cast using liquid epoxy under

vacuum giving void less encapsulation with high impulse strength. The HV coil are

made by employing are special winding arrangement to provide BIL level same as

that of oil filled up to a level of 170 KVP for 33KV class transformer.

5. SHORT CIRCUIT WITH STAND CAPABILITY: The glass epoxy

laminate insulation provides windings with most dynamic short circuit strength which

exceeds that of oil filled or conventional DTT.

Infect three same material is used in other commercial products like skis, tension

chain and tools where full advantage of mechanical strength is taken.

6. RESISTENCE AGAINST TEMPRATURE FLUCHUATION: The

insulation system withstands even the most extreme temperature fluctuation. Is

service temperature of class F i.e. 155C can be safely reached and transformer can

operate at this temperature continuously.

7. SPACE SAVING: The cast resin transformers have generally small dimensions

and are also less in weight. This reduces transportation and installation casts for

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substation. Also no special construction like brick laid rooms are requires for indoor

installation. The transformer in steel housing can be located directly adjacent to other

switchgear control cubicles. This provides compact design for substation.

8. HIGH OVER LOAD CAPACITY: Due to high time constant of dry type

winding the cast coil can be overloaded for short duration for higher overloads than

oil immerged transformer. The transformer especially suitable for rectifier and

convertor duties because of it.

9. LOWER LOSSES AND HIGHER EFFICIENCY: For DTT above 1000

KVA the overall losses are less compared to that of oil filled transformer of same

rating. This result in direct saving I form of loss capitalization and higher operating

efficiencies.

10. INCREASE IN PERFORMANCE BY FORCED COOLING: The

capacity of cast resin transformer can be increased up to 40% by forced cooling. Two

fans are provided on one side of transformer with duct extending directly below the

coils to cool the windings. The fans are controlled by the temperature and are

switched of as soon as the temperature goes below a certain specified temperature.

However continuous forced air operation is not recommended as the losses and the

noise generated by the fan makes the operation unattractive.

11. HIGHER RELIABILITY: The cast resin transformer have a very low failure

rate of less than one in one thousand and have a life of 20 years compared to oil filled

transformer having a average life span of 3 to 4 years only. This coupled with

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maintenance free nature and decentralized power distribution system provide an

economical alternative to oil filled transformers over a period of time.

APPLICATION:

Power Plants

Static Excitation Equipments

Steel Rolling mills

Oil Rigs and Refineries

Under Ground Substation and Mining

Chemical and Fertilizer Plant

Metro Railway

High Rise Buildings

Cinema Halls & Hospitals

PRODUCT RANGE:

Rating (KVA) – 10-10,000 KVA

Rated Voltage - up to 33 KV

BIL - up to 170 KVP

Insulation Class - F

Frequency - 50 to 60 Hz

Winding Arrangement - Dual Ratio & 3 windings

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Voltage Variation - Off circuit

CONSTRUCTIONAL FEATURES:

1. CORE: Cold Rolled Grain Oriented Silicon Steel (CRGOS).

2. WINDING: Electrolyte grade copper with high quality fiber glass

3. RASIN ENCAPSULATION: Internationally proven system of epoxy resin casting

4. ENCLOSURE: 2mm thick CRC steel, Ventilated enclosure

5. FITTING: Standard fitting such as lifting lugs, bidirectional flat rollers or skids, etc

6. PROTECTION: Thermal Protection by a system of thermistors embedded on the top of

the LV winding

ENGINEERING AND R&D CAPABILITIES:

Designs and drawings are made by hand/computer

Mainframe computers and CAD work stations are available

Technology is based on M/S may & Christie Germany (now knows Skoda Ltd ) who are

pioneer in world for manufacture of dry type cast resin transformers for the last 30

years.

For R&D work, BHEL corporate research and development center has been sat up in

Hyderabad.

MANUFACTURING FACILITIES:

Thin film design maker – manufactured by HEDRICH, Germany.

High vacuum casting chamber – manufactured by VPI, pune.

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Heating ovens – M/S THERMELEK, Bangalore

Coil winding machine

Coil cutting machine

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