Electric power principles sources, conversion, distribution and use

ELECTRIC POWER PRINCIPLES ELECTRIC POWER PRINCIPLES Sources, Conversion, Distribution and Use James L Kirtley Massachusetts Institute of Technology, USA A John Wiley and Sons, Ltd., Publication This edition first published 2010 C 2010 John Wiley & Sons, Ltd Registered office John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom For details of our global editorial offices, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com The right of the author to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic books Designations used by companies to distinguish their products are often claimed as trademarks All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners The publisher is not associated with any product or vendor mentioned in this book This publication is designed to provide accurate and authoritative information in regard to the subject matter covered It is sold on the understanding that the publisher is not engaged in rendering professional services If professional advice or other expert assistance is required, the services of a competent professional should be sought MATLAB R is a trademark of The MathWorks, Inc., and is used with permission The MathWorks does not warrant the accuracy of the text or exercises in this book This book’s use or discussion of MATLAB R software or related products does not constitute endorsement or sponsorship by The MathWorks of a particular pedagogical approach or particular use of MATLAB R software Library of Congress Cataloging-in-Publication Data Kirtley, James L Electric power principles: sources, conversion, distribution and use / James L Kirtley p cm Includes index ISBN 978-0-470-68636-2 (cloth) Electric power production I Title TK1001.K544 2010 621.3–dc22 2010010755 A catalogue record for this book is available from the British Library ISBN: 978-0-470-68636-2 Typeset in 10/12pt Times by Aptara Inc., New Delhi, India Printed in Singapore by Markono Print Media Pte Ltd Contents Preface xi 1.1 1.2 Electric Power Systems Electric Utility Systems Energy and Power 1.2.1 Basics and Units Sources of Electric Power 1.3.1 Heat Engines 1.3.2 Power Plants 1.3.3 Nuclear Power Plants 1.3.4 Hydroelectric Power 1.3.5 Wind Turbines 1.3.6 Solar Power Generation Electric Power Plants and Generation Problems 3 10 12 15 15 AC Voltage, Current and Power Sources and Power 2.1.1 Voltage and Current Sources 2.1.2 Power 2.1.3 Sinusoidal Steady State 2.1.4 Phasor Notation 2.1.5 Real and Reactive Power Resistors, Inductors and Capacitors 2.2.1 Reactive Power and Voltage 2.2.2 Reactive Power Voltage Support Problems 17 17 17 18 18 19 19 21 22 23 26 Transmission Lines Modeling: Telegrapher’s Equations 3.1.1 Traveling Waves 3.1.2 Characteristic Impedance 3.1.3 Power 3.1.4 Line Terminations and Reflections 31 32 33 33 35 35 1.3 1.4 1.5 2.1 2.2 2.3 3.1 vi 3.2 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 6.3 7.1 7.2 7.3 Contents 3.1.5 Sinusoidal Steady State Problems 40 42 Polyphase Systems 4.0.1 Two-Phase Systems Three-Phase Systems Line–Line Voltages 4.2.1 Example: Wye and Delta Connected Loads 4.2.2 Example: Use of Wye–Delta for Unbalanced Loads Problems 45 45 47 49 50 52 54 Electrical and Magnetic Circuits Electric Circuits 5.1.1 Kirchoff’s Current Law (KCL) 5.1.2 Kirchoff’s Voltage Law (KVL) 5.1.3 Constitutive Relationship: Ohm’s Law Magnetic Circuit Analogies 5.2.1 Analogy to KCL 5.2.2 Analogy to KVL: Magnetomotive Force 5.2.3 Analogy to Ohm’s Law: Reluctance 5.2.4 Simple Case 5.2.5 Flux Confinement 5.2.6 Example: C-Core 5.2.7 Example: Core with Different Gaps Problems 57 57 57 58 58 60 60 61 61 62 63 63 64 66 Transformers Single-phase Transformers 6.1.1 Ideal Transformer 6.1.2 Deviations from Ideal Transformer Three-Phase Transformers 6.2.1 Example Problems 71 71 72 73 75 77 80 Polyphase Lines and Single-Phase Equivalents Polyphase Transmission and Distribution Lines 7.1.1 Example Introduction To Per-Unit Systems 7.2.1 Normalization Of Voltage and Current 7.2.2 Three-Phase Systems 7.2.3 Networks with Transformers 7.2.4 Transforming from one base to another 7.2.5 Example: Fault Study Appendix: Inductances of Transmission Lines 7.3.1 Single Wire 7.3.2 Mutual Inductance 85 85 87 88 88 90 90 91 92 94 94 96 Contents 7.4 8.1 8.2 8.3 8.4 8.5 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 7.3.3 Bundles of Conductors 7.3.4 Transposed Lines Problems vii 96 97 98 Electromagnetic Forces and Loss Mechanisms Energy Conversion Process 8.1.1 Principle of Virtual Work 8.1.2 Coenergy Continuum Energy Flow 8.2.1 Material Motion 8.2.2 Additional Issues in Energy Methods 8.2.3 Electric Machine Description 8.2.4 Field Description of Electromagnetic Force: The Maxwell Stress Tensor 8.2.5 Tying the MST and Poynting Approaches together Surface Impedance of Uniform Conductors 8.3.1 Linear Case 8.3.2 Iron 8.3.3 Magnetization 8.3.4 Saturation and Hysteresis 8.3.5 Conduction, Eddy Currents and Laminations 8.3.6 Eddy Currents in Saturating Iron Semi-Empirical Method of Handling Iron Loss Problems 103 103 104 108 110 111 112 116 Synchronous Machines Round Rotor Machines: Basics 9.1.1 Operation with a Balanced Current Source 9.1.2 Operation with a Voltage Source Reconciliation of Models 9.2.1 Torque Angles Per-Unit Systems Normal Operation 9.4.1 Capability Diagram 9.4.2 Vee Curve Salient Pole Machines: Two-Reaction Theory Synchronous Machine Dynamics Synchronous Machine Dynamic Model 9.7.1 Electromagnetic Model 9.7.2 Park’s Equations 9.7.3 Power and Torque 9.7.4 Per-Unit Normalization 9.7.5 Equivalent Circuits 9.7.6 Transient Reactances and Time Constants Statement of Simulation Model 9.8.1 Example: Transient Stability 145 146 147 147 150 150 151 152 153 153 154 157 159 159 160 164 164 167 168 169 170 118 120 124 124 128 128 129 131 133 136 139 viii 9.9 9.10 9.11 Contents 9.8.2 Equal Area Transient Stability Criterion Appendix: Transient Stability Code Appendix: Winding Inductance Calculation 9.10.1 Pitch Factor 9.10.2 Breadth Factor Problems 10 10.1 10.2 170 173 176 180 180 182 System Analysis and Protection The Symmetrical Component Transformation Sequence Impedances 10.2.1 Balanced Transmission Lines 10.2.2 Balanced Load 10.2.3 Possibly Unbalanced Loads 10.2.4 Unbalanced Sources 10.2.5 Rotating Machines 10.2.6 Transformers 10.3 Fault Analysis 10.3.1 Single Line–neutral Fault 10.3.2 Double Line–neutral Fault 10.3.3 Line–Line Fault 10.3.4 Example of Fault Calculations 10.4 System Protection 10.4.1 Fuses 10.5 Switches 10.6 Coordination 10.6.1 Ground Overcurrent 10.7 Impedance Relays 10.7.1 Directional Elements 10.8 Differential Relays 10.8.1 Ground Fault Protection for Personnel 10.9 Zones of System Protection 10.10 Problems 185 185 188 188 189 190 191 193 193 197 198 199 200 201 205 206 207 208 208 208 209 210 211 212 212 11 11.1 219 219 221 222 224 226 226 227 228 228 229 231 11.2 11.3 11.4 11.5 11.6 11.7 Load Flow Two Ports and Lines 11.1.1 Power Circles Load Flow in a Network Gauss–Seidel Iterative Technique Bus Admittance 11.4.1 Bus Incidence 11.4.2 Alternative Assembly of Bus Admittance Example: Simple Program 11.5.1 Example Network MATLAB Script for the Load Flow Example Problems ... ELECTRIC POWER PRINCIPLES ELECTRIC POWER PRINCIPLES Sources, Conversion, Distribution and Use James L Kirtley Massachusetts Institute of Technology, USA A John Wiley and Sons, Ltd.,... Electric Power Systems Electric Utility Systems Energy and Power 1.2.1 Basics and Units Sources of Electric Power 1.3.1 Heat Engines 1.3.2 Power Plants 1.3.3 Nuclear Power Plants 1.3.4 Hydroelectric... (hydroelectric power) , and heat from nuclear fission There are small but rapidly growing amounts of electric power generated from wind and solar sources and some Electric Power Principles: Sources,