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1、 IEEE Std 81.2-1991 IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or Interconnected Grounding Systems Sponsor Power System Instrumentationand Measurements Committee of the IEEE Power Engineering Society Approved December 5, 1991 IEEE Standards Board Abstract:
2、Practical instrumentation methods are presented for measuring the ac characteristics of large, extended or interconnected grounding systems. Measurements of impedance to remote earth, step and touch potentials, and current distributions are covered for grounding systems ranging in complexity from sm
3、all grids (less than 900 m 2 ), with only a few connected overhead or direct burial bare concentric (2) neutrals, to large grids (greater than 20 000 m 2 ), with many connected neutrals, overhead ground wires (sky wires), counterpoises, grid tie conductors, cable shields, and metallic pipes. This st
4、andard addresses measurement safety; earth-return mutual errors; low-current measurements; power-system staged faults; communication and control cable transfer impedance; current distribution (current splits) in the grounding system; step, touch, mesh, and profile measurements; the foot-equivalent e
5、lectrode earth resistance; and instrumentation characteristics and limitations. Keywords: Grounding systems, impedance, safety The Institute of Electrical and Electronics Engineers, Inc. 345 East 47th Street, New York, NY 10017-2394, USA Copyright 1992 by the The Institute of Electrical and Electron
6、ics Engineers, Inc. All rights reserved. Published 1992 Printed in the United States of America ISBN 1-55937-187-0 No part of this publication may be reproduced in any form, in an electronic retrieval system or other wise, without the prior written permission of the publisher. Copyright The Institut
7、e of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 11:45:23 MDTNo reproduction or networking permitted without license from IHS -,-,- IEEE Standards documents are developed within the Techni
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16、331 Piscataway, NJ 08855-1331 USA IEEE Standards documents are adopted by the Institute of Electrical and Electronics Engineers without regard to whether their adoption may involve patents on articles, materials, or processes. Such adoption does not assume any liability to any patent owner, nor does
17、 it assume any obligation whatever to parties adopting the standards documents. Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 11:45:23 MDTNo reproduction or networ
18、king permitted without license from IHS -,-,- iii Foreword (This foreword is not a part of IEEE Std 81.2-1991, IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or Interconnected Grounding Systems.) During the late 1970s, in an effort to increase its usefulness, t
19、his guide was divided into two parts. The rst part is entitled IEEE Std 81-1983, IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Ground System. It covers the majority of eld measurements that do not require special high-precision equipment and measurin
20、g, and that do not encounter unusual difculties such as may be found with extensive grounding systems, abnormally high stray ac or dc currents, etc. IEEE Std 81 (Part I) has been extensively revised and updated. Part I was approved in 1983 and reafrmed in 1991. This part of the guide (Part II) is en
21、titled IEEE Std 81.2- 1991, IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or Interconnected Grounding Systems. This new part covers measurement of very low values of ground impedance (less than 1 W ). The extensive use of specialized instrumentation, measuring
22、 techniques, and safety aspects are incorporated. This guide was prepared by the Measurement of Impedance and Safety Characteristics of Large, Extended or Interconnected Grounding Systems Working Group of the RLC Measurements Subcommittee of the Power Systems Instrumentation and Measurements Committ
23、ee of the IEEE Power Engineering Society. At the time that this standard was completed, the working group had the following membership: D. Mukhedkar , Chair J. White , Secretary E. Rogers, Technical Editor G. Y. R. Allen M. J. Anna E. P. Dick J. Fortin W. Hardy P. Kouteynikoff J. F. Laidig R. Malews
24、ki A. Pessonen R H. Reynolds H. Sarmiento A. N. Sharaf E. Smithson L. Thione W. Velazquez At the time that it balloted and approved this standard for submission to the IEEE Standards Board, the Power Systems Instrumentation and Measurements Committee had the following membership: A. Abramowitz J. An
25、derson J. M. Belanger J. M. Carr C. Carrara L. Coffeen S. W. Crampton F. C. Creed V. DaGrosa A. E. Emmanuel G. J. Fitzpatrick R. E. Hebner R. Hopkins P. B. Jacob W. A. Keagle, Jr. H. Kirkham J. A. Kise S. R. Knudsen J. Kuffel D. W. Lenk F. J. Levitsky R. Malewski D. McAuliff T. R. McComb J. H. Moran
26、 D. Mukhedkar O. Petersons R. Reid P. H. Reynolds R. L. Richardson A. F. Rohlfs H. M. Schneider J. C. Smith E. So G. E. Stemler D. Train R. S. Turgel J. M. Vanderleck C. F. Von Herrmann B. H. Ward D. L. Whitehead Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS u
27、nder license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 11:45:23 MDTNo reproduction or networking permitted without license from IHS -,-,- iv When the IEEE Standards Board approved this standard on December 5, 1991, it had the following membership: Marco W. Mi
28、gliaro , Chair Donald C. Loughry , Vice Chair Andrew G. Salem , Secretary Dennis Bodson Paul L. Borrill Clyde Camp James M. Daly Donald C. Fleckenstein Jay Forster* David F. Franklin Ingrid Fromm Thomas L. Hannan Donald N. Heirman Kenneth D. Hendrix John W. Horch Ben C. Johnson Ivor N. Knight Joseph
29、 Koepfinger* Irving Kolodny Michael A. Lawler John E. May, Jr. Lawrence V. McCall T. Don Michael* Lloyd A. Pete Morley Stig L. Nilsson John L. Rankine Ronald H. Reimer Gary S. Robinson Terrance R. Whittemore *Member Emeritus Also included are the following nonvoting IEEE Standards Board liaisons: Fe
30、rnando Aldana Satish K. Aggarwal James Beall Richard B. Engelman Stanley Warshaw Adam Sicker IEEE Standards Project Editor Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21
31、/2007 11:45:23 MDTNo reproduction or networking permitted without license from IHS -,-,- v CLAUSEPAGE 1. Purpose1 2. Scope.1 3. References.2 4. Safety Practices.3 4.1 General Precautions . 3 4.2 Safety Aspects of Test Preparations. 3 4.3 Safety Aspects of Test Measurements. 4 5. Factors Effecting Gr
32、ounding System Measurements4 6. Preliminary Planning and Procedures.6 6.1 Distance to Current and Potential Test Electrodes. 6 6.2 Selection of Test-Conductor Routing and Test-Probe Locations 6 6.3 Determining the Effect of Overhead-Ground-Wire Shielding on Test Current Distribution 7 6.4 Estimating
33、 Grounding Grid Impedance. 7 6.5 Estimating Minimum Test Current 7 6.6 Test Current Sources 7 6.7 Estimating Test-Current Source Requirements 8 6.8 Remote Rod Electrode Current Capacity. 8 6.9 Potential Input Impedance . 9 6.10 Determining Grounding System Connection Condition 9 6.11 Establishing th
34、e Measurement Point on a Grounding System. 9 7. Earth-Return Mutual Effects When Measuring Grounding-System Impedance 9 7.1 Introduction 9 7.2 Measurement Error Due to Earth Mutual Resistances. 10 7.3 Measurement Error Due to AC Mutual Coupling 10 7.4 Mutual Coupling to Potential Lead From Extended
35、Ground Conductors . 12 8. Measurement of Low-Impedance Grounding Systems by Test-Current Injection.12 8.1 Introduction 12 8.2 Signal Generator and Power Amplifier Source 13 8.3 Portable Power-Generator Source 16 8.4 Power System Low-Voltage Source 20 9. Measurement of Low-Impedance Grounding Systems
36、 by Power System Staged Faults.23 9.1 Introduction 23 9.2 Fault Configurations 24 9.3 Fault Initiation 24 9.4 Current Measurements. 25 9.5 Potential Measurements. 25 9.6 Interference Reduction. 27 9.7 Calibration 28 Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IH
37、S under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 11:45:23 MDTNo reproduction or networking permitted without license from IHS -,-,- vi CLAUSEPAGE 10. Current Distribution in Extended Grounding Systems.30 10.1 Introduction. 30 10.2 Test Considerations
38、 31 10.3 Analysis of Current Distribution in a Grounding System (See B25 and B44). 33 10.4 Induced Current in the Angled Overhead Ground Wire 37 10.5 Current Distribution During a Staged Fault Test (See B44). 41 11. Transfer Impedances to Communication or Control Cables.49 12. Step, Touch, and Volta
39、ge-Profile Measurements .51 12.1 General Requirements 51 12.2 Grid Safety Requirements 52 12.3 Footprint-Electrode Method. 52 12.4 Test-Probe Method. 52 12.5 Simulated-Personnel Method (See B24). 54 13. Instrumentation Components56 13.1 Introduction 56 13.2 Direct-Reading Ohmmeters . 57 13.3 Electro
40、magnetic Oscillograph 57 13.4 Tuned Voltmeter 58 13.5 Fast Fourier Transform Analyzer. 58 13.6 Sine Wave Network Analyzer 58 13.7 Staged Fault 59 13.8 Switched Power-Frequency Source. 59 13.9 Welding Set or Portable Power Generator. 59 13.10 Low-Power Sine Wave Source. 60 13.11 Low-Power Random Nois
41、e Source. 60 13.12 Periodic (Nonsinusoidal) Generator 60 13.13 Power-System Switching Transient 60 13.14 Pulse Generator. 61 13.15 Current Transformer (CT). 61 13.16 Resistive Shunt 61 13.17 Inductive Current Pickup 61 13.18 Hall-Effect Probe 62 13.19 Remote Synchronization of Test Signal 62 13.20 M
42、easurement Environment and Signal Transmission. 62 14. Instrument Performance Parameters.64 14.1 Reading Accuracy. 64 14.2 Selectivity 64 14.3 Impedance Phase Discrimination 67 14.4 Current Level 68 14.5 Test Frequency and Current Waveform 68 14.6 Measurement Error Reduction (See B25) 69 15. Bibliog
43、raphy69 Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IEEELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 11:45:23 MDTNo reproduction or networking permitted without license from IHS -,-,- vii CLAUSEPAGE Annex A Mut
44、ual Impedance Between Horizontal Earth-Return Conductors and the Self Impedance of a Horizontal Earth-Return Conductor Based on the Complex Image Plane Concept (See 11) (Informative)73 Annex B Mutual Impedance Between Finite Length Conductors Lying on the Ground Based on the Campbell/Foster Method (
45、Informative)84 Annex C Earth Return Impedance of a Grid-Tie Conductor (Informative)89 Annex D Parallel Impedance of an Overhead Ground Wire and a Buried Counterpoise Conductor (Informative).91 Copyright The Institute of Electrical and Electronics Engineers, Inc. Provided by IHS under license with IE
46、EELicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 11:45:23 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright 1992 IEEE All Rights Reserved 1 IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or Interconne
47、cted Grounding Systems 1. Purpose The purpose of this guide is to present practical instrumentation methods that may be used for the measurement of impedance to remote earth, step and touch potentials, and current distributions of large extended or interconnected grounding systems ranging in complex
48、ity from small grids (less than 900 m 2 ), with only a few connected overhead or direct burial bare concentric neutrals, to large grids (greater than 20 000 m 2 ), with many connected neutrals, overhead ground wires (sky wires), counterpoises, grid tie conductors, cable shields, and metallic pipes. 2. Scope Test methods and instrumentation techniques used to measure the ac characteristics of large grounding systems include the following topics: 1)Measurement safety 2)Earth-return mutual errors 3)Low-current measurements 4)Pow