Table Of Content,.--
I
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Electrical Engineer’s
Handbook
Newnes
Electrical Engineer’s
Handbook
D.F. Warne
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OXFORD AUCKIAND BOSTON JOHANNESBURG MELBOURNE NEW DELHl
Newnes
An imprint of Butterworth-Heinemann
Linacre House, Jordan Hillt Oxford OX2 8DP
225 Wildwood Avenue, Woburn, MA 01801-2041
A division of Reed Educational and Professional Publishing Ltd
A member of the Reed Elsevier plc group
First published 2000
Q D.F. Warne 2000
All rights reserved. No part of this publication
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British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library
ISBN 0 7506 4879 1
Library of Congress Cataloguing in Publication Data
A catalogue record for this book is available from the
British Library of Congress
Typeset at Replika Press Pvt Ltd, 100% EOU, Delhi 110 040, India
Printed and bound in Great Britain by Biddles Ltd
wwv.b iddlesxo.u k
Contents
Acknowledgements xv
1 Introduction 1
2 Principles of electrical engineering 3
2.1 Nomenclature and units 3
2.2 Electromagnetic fields 3
2.2.1 Electric fields 3
2.2.2 Electric currents 5
2.2.3 Magnetic fields 7
2.2.4 Electromagnetism 10
2.3 Circuits 11
2.3.1 DC circuits 11
2.3.2 AC circuits 14
2.3.3 Magnetic circuits 18
2.4 Energy and power 20
2.4.1 Mechanical energy 20
2.4.2 Electrical energy 21
2.4.3 Per-unit notation 24
2.4.4 Energy transformation effects 24
3 Materials For electrical engineering 29
3.1 Introduction 29
3.2 Magnetic materials 29
3.2.1 Soft (high-permeability) materials 32
3.2.1.1 Sheet steels 32
3.2.1.2 Amolphous alloys 33
3.2.1.3 Nickel-iron alloys 34
3.2.1.4 Ferrires and garnets 34
3.2.1.5 Sofl magnetic composites 35
3.2.2 Hard (permanent magnet) materials 35
3.2.2.1 Alnico alloys 35
3.2.2.2 Ferrites 35
3.2.2.3 Rare earth alloys 36
3.2.2.4 Bonded magnets 37
3.2.2.5 Applications 37
3.2.3 Other materials 37
3.2.4 Standards 38
3.3 Insulating materiaIs 39
3.3.1 Solid dielectrics 41
3.3.1.1 Inorganic (cemka nd glass) materials 41
3.3.1.2 Plastic films 42
3.3.1.3 Flexible insulating slceving 42
3.3.1.4 Rigid fibrous reinforred laminates 42
vi Contents
3.3.1.5 Resins and varnishes 42
3.3.1.6 Pressure-sensitive adhesive tapes 43
3.3.1.7 Cellulosic materials 43
3.3.1.8 Combined flexible materials 43
3.3.1.9 Mica products 43
3.3.1.10 Textile insulation 46
3.3.1.11 Elastomers and thermoplastics 46
3.3.2 Liquid dielectrics 46
3.3.3 Gas insulation 46
3.3.4 Vacuum insulation 47
3.3.5 Standards 47
3.4 Conducting materials 48
3.4.1 Conductors 48
3.4.1.1 Copper and its alloys 49
3.4.1.2 Aluminium and its alloys 52
3.4.1.3 Resistance alloys 53
3.4.2 Semiconductors 54
3.4.2.1 Impurity effects and doping 55
3.4.2.2 The transistor 55
3.4.2.3 Printed circuits and integrated circuias 57
3.4.2.4 The microprocessor 57
3.4.3 Superconductors 58
3.5 Standards 59
4 Measurement and instrumentation 61
4.1 Introduction 61
4.2 The oscilloscope 62
4.2.1 The cathode ray oscilloscope 62
4.2.2 The steady display of a repetitive signal 64
4.2.3 The display of one signal against another - Lissajous figures 64
4.2.4 The display of two signals against time 66
4.2.5 The acldc switch 68
4.2.6 The loading effect of the CRO 69
4.2.7 CRO probes 70
4.2.8 CRO bandwidth and the measurement of rise time 71
4.2.9 The high bandwidth CRO 72
4.2.10 The digital storage oscilloscope 72
4.3 Digital frequency counters, voltmeters and multimeters 74
4.3.1 The frequency counter 74
4.3.1.1 The measurement of low fizquencies 75
4.3.1.2 The accuracy of the frequency counter 76
4.3.2 The digital voltmeter 76
4.3.3 The digital multimeter 77
4.4 Sensors 78
4.4.1 The strain gauge 79
4.4.2 The piezoelectric accelerometer 80
4.4.3 The linear variable differential transformer 81
4.5 The international measurement system, traceability and
calibration 82
Contents vii
5 Generators 85
5.1 Introduction 85
5.2 Main generator types 85
5.3 Principles of operation 87
5.3.1 No-load operation 87
5.3.2 The effect of load 92
5.3.3 Damping of transients 93
5.3.4 Voltage waveform 94
5.4 The Automatic Voltage Regulator (AVR) 95
5.5 Brushless excitation 97
5.5.1 Separate exciter 98
5.5.2 Capacitor excitation 100
5.5.3 Induction generator 100
5.6 Construction 101
5.6.1 Stator 10 1
5.6.2 Rotor 102
5.6.3 Cooling 102
5.7 Rating and specification 104
5.7. I Rated output 104
5.7.2 Reactances 106
5.7.3 Main items of specification 107
5.8 Testing 107
5.9 Standards 108
6 Transformers 109
6.1 Principles of operation 109
6.2 Main features of construction 113
6.2.1 The core 113
6.2.2 Windings 116
6.2.3 Winding connections 117
6.2.4 Bushings 122
6.2.5 Tapchangers 122
6.2.6 Cooling equipmnt 127
6.3 Main classes of transformer 127
6.3.1 Transformers for electronics 127
6.3.2 Small transformers 127
6.3.3 Distribution transformers 128
6.3.4 Supply transformers 129
6.3.5 Transmission (or intertie) u-ansformers 130
6.3.6 Generator (or stepup) transformers 130
6.3.7 Phase-shifting transformers 131
6.3.8 Converter transformers 131
6.3.9 Railway transformers 133
6.3.10 Rectifier and furnace transformers 133
6.3.11 Dry-typ transformers 133
6.3.12 Gas-fiLled transformers 133
