Design of transformers / Indrajit Dasgupta.

Format:

Book

Author/Creator:

Dasgupta, Indrajit, author.

Series:

McGraw-Hill's AccessEngineering

Language:

English

Subjects (All):

Electric transformers--Design.

Electric transformers.

Electric insulators and insulation--Oils.

Electric insulators and insulation.

Genre:

Electronic books.

Physical Description:

1 online resource

Edition:

First edition.

Place of Publication:

New York, N.Y. : McGraw-Hill Education, [2002]

Language Note:

In English.

Summary:

Annotation Currently, the installed capacity of power generation in India is 104,917 MW and by 2012 another 100,000 MW will be added. With this addition, the requirement of power and distribution transformers will grow enormously, as will the emphasis on quality and performance. The design of a transformer is critical to its quality as are men, machines and materials. This book is a hands-on guide covering design, process control of manufacturing technique, installation, erection, commissioning and maintenance of distribution transformers. It also covers failure analysis and remedial measures for increasing the longevity of transformers. Apart from explaining the design aspect of transformers, the book lists the requirements of ISO 9000 in the process of manufacturing technique up to the final stages of product testing, inspection and despatch.

Contents:

A. Dedication

B. Preface

C. Acknowledgements

D. At a glance

Chapter 1 working principle of a transformer

Chapter 2 requirements of transformer specifications from end-users

Chapter 3 basic materials and their processing

Chapter 4 the basic concept of design

Chapter 5 design of the 100 kva transformer

Chapter 6 design of the 630 kva transformer

Chapter 7 design of the 5 mva, 33/11 kv transformer

Chapter 8 the design concept of the distribution transformers under repair contract

Chapter 9 the basic concept of computer-aided design

Chapter 10 dry-type distribution transformers with polyestermide vpi?a new concept in india

Chapter 11 process control

Chapter 12 a schedule of tests and their procedures

Chapter 13 user's installation and instruction manual for transformers in services

Chapter 14 draft specification for the 25, 63 and 100 kva, 11/0.433 kv aluminium-wound conventional type distribution transformers

Chapter 15 nature of failures and their causes

Chapter 16 conclusion

E. List of abbreviations

1. Working principle of a transformer

Introduction

The working principle

The formula for induced emf

Alignment chart

Shell and core type transformer

Transformer cores

Windings and insulations

End-turn insulation

Transformer losses

The power scenario in india

Summary

2. Requirements of transformer specifications from end-users

Requirement of specification

Mandatory specification

Supplementary specification

Additional specification

Requirement fill-up standard gtp format

3. Basic materials and their processing

Crgo (stacked core)

Crgo slitting

Types of slitter lines

Layout of a slitter line

Requirement of slitting operation

Construction of blade

Recommendations for better slitting

Clearance adjustment operations

Influence of shear angle at slitting (grain-oriented)

Hold the strips near the blade firmly with the stabilizer

Crgo steel processing

Annealing

Core-building

Step-lap

Winding wires and strips

Processing wire drawing

Die materials

Processing strip drawing

Annealing of wires and strips

Annealing of copper

Annealing of aluminium

Insulating paper

Paper covering on the conductor

Tests on paper covered conductor

Reference iss for wires and strips

Details of machineries for wires and strips

Process chart

Choice of using copper or aluminium as winding material

Insulating oil

Chemistry of transformer oil

Refining of tofs

Characteristic properties and specification

Storage and handling of transformer oil

Dedicated handling

Transport in tankers or drums

Compatibility and contaminants

Other major raw materials and components

Summary.

4. The basic concept of design

Selection of number of turns

Selection of the core diameter

Selection of winding wires and strips

Calculation of size of a high-voltage conductor

Calculation of size of a low-voltage conductor

Transposition

Process flow chart

5. Design of a 100 kva transformer

Proposed specification

Primary coil

Secondary coil

Core diameter

Step width

Core stack

Core area

Flux density

Coil diameter and core limb centre

Core details

Approximate weight of core

Step-wise weight calculation of core

Winding details

Coil assembly

Weight of lv and hv aluminium

Winding resistance and load loss

No-load loss

No-load current

Percentage reactance, resistance and impedance

Ratio error at different tap positions

Efficiency

Maximum efficiency

Regulations

Performance figures

Design outputs

The design of tank

Radiators

Weight of tank

Core fittings, tie rods and core studs

Volume of oil

Overall weights and dimensions

Preparation of drawings and gtp

Conclusion

6. Design of the 630 kva transformer

Primary coil (connected in delta)

Secondary coil (connection star)

Stepwise weight calculation of core

Coil assembly specification

Weight of lv and hv copper

Design of tank

Non-magnetic welding

7. Design of the 5 mva, 33/11 kv transformer

Selection of primary and secondary conductor

Number of turns

Disc details of coils

Formation of lv coil

Formation of hv coil

Amp-turns balancing

Winding specification

Weight of secondary and primary windings

Winding resistances and load loss

Design output

8. The design concept of distribution transformers under repair contract

Basic requirement

Basic input of design

Progress of designing a repair transformer

Design procedure

Lv and hv conductor weight

Placement of hv coil

Calculation of winding resistances and load loss

Impedance

Winding specification and assembly details

Other aspects of design

Cleaning of crgo laminations and tank

Final assembly and testing

9. The basic concept of computer-aided design

Basic concept of computer-aided design

Who all can handle computer-aided design

Specified-need of the specification

Implied-needs of the specification

Computer programming

Variable inputs

Review of the figures which are fed as variable inputs

Operation

Non-converging

Design modification

Other aspects of the design

Design validation

Design package

Computer design print-out

10. Dry-type distribution transformers with polyesterimide vpi (a new concept in india)

Dry-type transformer

Insulation system

Impregnant

Vpi plant requirements

Economic impregnation

Application of dry-type transformer

11. Process control

Role of the machine

Machine maintenance

Role of materials

Role of men

The manufacturing process

Inprocess inspection

Proto-type results

12. Schedule of tests and their procedures

A schedule of tests

Procedure of tests

Test sl. No. 1: separate source power frequency test on hv and lv winding (routine test)

Test sl. No. 2: induced over voltage test (routine test)

Test sl. No. 3: insulation resistance of hv and lv windings (routine test)

Test sl. No. 4: di-electric value of insulating oil (acceptance test)

Test sl. No. 5: measurement of winding resistance (routine test)

Test sl. No. 6: measurement of no-load loss and no-load current (routine test)

Test sl. No. 7: measurement of load loss and impedance (routine test)

Test sl. No. 8: voltage ratio and phase relationship (routine test)

Test sl.no.9: temperature rise test (type test)

Test sl. No. 10: lightning impulse test (type test)

Test sl. No. 11: requirement and procedure with regard to ability to withstand short-circuit test (special test)

Test sl. No. 12: un-balance current on lv neutral (special test)

Test sl. No. 13: zero sequence impedance (special test)

Test sl. No. 14: magnetic balance test (special test)

Test sl. No. 15: measurement of noise level (special test)

13. User's installation and instruction manual for transformers in services

Installation

Oil

Drying of transformer at site

Gasket and gasket joints

Cable box

Conservator

Silicagel breather

Explosion vent

Buchholz relay

Temperature indicator

Off-circuit tap switch

Earthing

Minimum acceptable insulation resistance

Painting

Completion of erection work

Parallel operation

Testing and commissioning

Check list before commissioning

Energising

Maintenance

14. Draft specification for 25, 63 and 100 kva, 11/0.433 kv aluminium-wound conventional distribution transformers

Scope

Applicable standard

Rating

Rated frequency

Taps

Permissible flux density and over-fluxing

Current density

No-load voltage ratio

Transformer oil

Winding connections and vectors

Rating and terminal marking plate

Limits of temperature rise

Losses and impedance

Insulation level

Constructional features

Tank construction

Gaskets

Location of thermometer pocket

Surface preparation and painting

Core material and its construction

Base mounting arrangement

Clearances

Test and inspection

Procedure of inspection

Submittals

Tolerances

Deviation

Preference

Quality assurance plan

List of fittings and accessories

Schedule of guaranteed technical particulars for 25, 63 and 100 kva, 11/0.433 kv, aluminium-wound transformers

15. Nature of failures and their causes

Type of failure

Causes of failure

Analysis of faults

Cause of failure due to fault in the magnetic circuit

Cause of failure due to failure in the electric circuit

Failure due to external short-circuit

16. Conclusion

Annexure?a

17. Annexure?b

Short-circuit test.

Notes:

"Basic materials and their processing included; Design specs of 100 KVA, 630 KVA, 5MVA, 33/11 KV transformers covered; Process control based on ISO 9000, test, nature of failures and their causes discussed."-- Cover

Includes bibliographical references and index.

Electronic reproduction. New York, N.Y. : McGraw Hill, 2002. Mode of access: World Wide Web. System requirements: Web browser. Access may be restricted to users at subscribing institutions.

Description based on cover image and table of contents, viewed on Oct. 24, 2014.

Other Format:

Print version: Design of transformers.

ISBN:

9780070436404

0070436401

OCLC:

894357136

Access Restriction:

Restricted for use by site license.