Abb Protection Application Book.pdf

Protective Relaying Theory and Applications Edited by

Walter A. Elmore ABB Power T&D Company Inc. Relay Division Coral Springs, Florida

Marcel Dekker, Inc.

New York* Basel* Hong Kong

Portions of this book were originally published as Applied Protective Relaying, edited by J. L. Blackburn. Westinghouse Electric Corporation, Coral Springs, Florida © 1982. The publisher offers discounts on this book when ordered in bulk quantities. For more information, write to Special Sales/Professional Marketing at the address below. This book is printed on acid-free paper. Copyright © 1994 by ABB Power T&D Company [nc. All Rights Reserved. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher. Marcel Dekker, Inc. 270 Madison Avenue, New York, New York 10016 Current printing (last digit): 10 9 8 7 6~ 5 4 3 2 PRINTED IN THE UNITED STATES OF AMERICA

Preface

Protective relaying is a constantly changing and expanding science that challenges even those who are deeply and totally involved with it, such as the authors of this book. Changing technology—from electromechanical to discrete semiconductor, to integrated circuits, to microprocessor techniques—has enhanced the ability to solve old gnawing problems and is in itself a fascinating study. However, this book touches only lightly on the means of implementation and places primary emphasis on the basis by which relaying in any form can be applied to satisfy a functional need. Some chapters of this book draw heavily from a previous work, Applied Protective Relaying, that was developed and edited by J. Lewis Blackburn. All chapters have been revised, reflecting changes in practice, while some entirely new chapters were stimulated by the rapidly changing protective relaying technology. This volume describes, in the most basic terms, fundamental concepts of relaying without attempting to delineate all of the refinements for which experience has dictated a need. For complete details on any of these systems or units, the manufacturers1 literature remains the best guide. Much protective relaying technology becomes obscured over the years, and the reasons for certain practices become lost. One of the aspirations for this book is to preserve, as much as possible, the details of popular practice and to provide a lasting record of the reasons certain things are done, in the hope that a repclition of past oversights and errors can be avoided in the future. If one outage or one incorrectly labeled relay misoperalion can be avoided. this book will have accomplished another of its goals. In no sense does this book cover protective relaying completely. A second volume covering communications and microprocessor technology as related to protective relays is in development. This book serves as a text for the continuation of the protective relaying seminars (numbering now in the hundreds) that the authors have taught. It will also provide considerable insight to the individual who wishes to explore this fascinating field independently. Waiter A. Elmore

Contents

Preface

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1. Introduction and General Philosophies J. L. Blackburn (revised by W. A. Elmore) 1. 2. 3.

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6. 7.

Introduction .......................................................................................... .................................................................. Classification of Relays ........................................................................................................................................... 2.1 Analog/Digital/Numerical ............................................................................................................................... Protective Relaying Systems and Their Design...................................................................................................... 3.1 Design Criteria ............................................................................................................................................... 3.2 Factors Influencing Relay Performance......................................................................................................... 3.3 Zones of Protection........................................................................................ ............................................... Applying Protective Relays ............... .......................... ………............................................................................. 4.1 System Configuration..................................................................................................................................... 4.2 Existing System Protection and Procedures.................................................................................................. 4.3 Degree of Protection Required ..................................................................................................................... 4.4 Fault Study ..................................................................................................................................................... 4.5 Maximum Loads, Transformer Data, and Impedances................................................................................ Relays and Application Data.................................................................................................................................. 5.1 Switchboard Relays........................................................................................................................................ 5.2 Rack-Mounted Relays..................................................................................................................................... Circuit-Breaker Control ........................................................................................................................................... Comparison of Symbols ...........................................................................................................................................

2. Technical Tools of the Relay Engineer: Phasors, Polarity, and Symmetrical Components J. L. Blackburn (revised by W. A. Elmore) 1. 2.

3.

Introduction.............................................................................................................................................................. Phasors...................................................................................................................................................................... 2.1 Circuit Diagram Notation for Current and Flux ........................................................................................... 2.2 Circuit Diagram Notation for Voltage........................................................................................................... 2.3 Phasor Notation... .......................................................................................................................................... 2.4 Phasor Diagram Notation .............................................................................................................................. 2.5 Phase Rotation vs. Phasor Rotation............................................................................................................... Polarity in Relay Circuits ........................................................................................................................................ 3.1 Polarity of Transformers................................................................................................................................. 3.2 Polarity of Protective Relays .......................................................................................................................... 3.3 Characteristics of Directional Relays.............................................................................................................. 3.4 Connections of Directional Units to Three-Phase Power Systems ...............................................................

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