IEEE 81.2-1991 - IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or Interconnected Grounding Systems.pdf

1、 IEEE Std 81.2-1991IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or Interconnected Grounding SystemsSponsorPower System Instrumentationand Measurements Committeeof theIEEE Power Engineering SocietyApproved December 5, 1991IEEE Standards BoardAbstract: Practica

2、l instrumentation methods are presented for measuring the ac characteristics of large,extended or interconnected grounding systems. Measurements of impedance to remote earth, step andtouch potentials, and current distributions are covered for grounding systems ranging in complexity fromsmall grids (

3、less than 900 m2), with only a few connected overhead or direct burial bare concentric (2)neutrals, to large grids (greater than 20 000 m2), with many connected neutrals, overhead ground wires(sky wires), counterpoises, grid tie conductors, cable shields, and metallic pipes. This standard addressesm

4、easurement safety; earth-return mutual errors; low-current measurements; power-system staged faults;communication and control cable transfer impedance; current distribution (current splits) in the groundingsystem; step, touch, mesh, and profile measurements; the foot-equivalent electrode earth resis

5、tance; andinstrumentation characteristics and limitations.Keywords: Grounding systems, impedance, safetyThe Institute of Electrical and Electronics Engineers, Inc.345 East 47th Street, New York, NY 10017-2394, USACopyright 1992 by theThe Institute of Electrical and Electronics Engineers, Inc.All rig

6、hts reserved. Published 1992Printed in the United States of AmericaISBN 1-55937-187-0No part of this publication may be reproduced in any form, in an electronic retrieval system or other wise, without theprior written permission of the publisher.IEEE Standards documents are developed within the Tech

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16、atever to parties adopting the standardsdocuments.Foreword(This foreword is not a part of IEEE Std 81.2-1991, IEEE Guide for Measurement of Impedance and Safety Characteristics ofLarge, Extended or Interconnected Grounding Systems.)During the late 1970s, in an effort to increase its usefulness, this

17、 guide was divided into two parts. The rst part isentitled IEEE Std 81-1983, IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth SurfacePotentials of a Ground System. It covers the majority of eld measurements that do not require special high-precisionequipment and measuring, and

18、 that do not encounter unusual difculties such as may be found with extensivegrounding systems, abnormally high stray ac or dc currents, etc. IEEE Std 81 (Part I) has been extensively revised andupdated. Part I was approved in 1983 and reafrmed in 1991. This part of the guide (Part II) is entitled I

19、EEE Std 81.2-1991, IEEE Guide for Measurement of Impedance and Safety Characteristics of Large, Extended or InterconnectedGrounding Systems. This new part covers measurement of very low values of ground impedance (less than 1 W). Theextensive use of specialized instrumentation, measuring techniques,

20、 and safety aspects are incorporated.This guide was prepared by the Measurement of Impedance and Safety Characteristics of Large, Extended orInterconnected Grounding Systems Working Group of the RLC Measurements Subcommittee of the Power SystemsInstrumentation and Measurements Committee of the IEEE

21、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. AllenM. J. AnnaE. P. DickJ. FortinW. HardyP. KouteynikoffJ. F. LaidigR. MalewskiA. PessonenR H. Reynolds

22、H. SarmientoA. N. SharafE. SmithsonL. ThioneW. VelazquezAt the time that it balloted and approved this standard for submission to the IEEE Standards Board, the Power SystemsInstrumentation and Measurements Committee had the following membership:A. AbramowitzJ. AndersonJ. M. BelangerJ. M. CarrC. Carr

23、araL. CoffeenS. W. CramptonF. C. CreedV. DaGrosaA. E. EmmanuelG. J. FitzpatrickR. E. HebnerR. HopkinsP. B. JacobW. A. Keagle, Jr.H. KirkhamJ. A. KiseS. R. KnudsenJ. KuffelD. W. LenkF. J. LevitskyR. MalewskiD. McAuliffT. R. McCombJ. H. MoranD. MukhedkarO. PetersonsR. ReidP. H. ReynoldsR. L. Richardso

24、nA. F. RohlfsH. M. SchneiderJ. C. SmithE. SoG. E. StemlerD. TrainR. S. TurgelJ. M. VanderleckC. F. Von HerrmannB. H. WardD. L. WhiteheadiiiWhen the IEEE Standards Board approved this standard on December 5, 1991, it had the following membership:Marco W. Migliaro, Chair Donald C. Loughry, Vice Chair

25、Andrew G. Salem, Secretary Dennis BodsonPaul L. BorrillClyde CampJames M. DalyDonald C. FleckensteinJay Forster*David F. FranklinIngrid FrommThomas L. HannanDonald N. HeirmanKenneth D. HendrixJohn W. HorchBen C. JohnsonIvor N. KnightJoseph Koepfinger*Irving KolodnyMichael A. LawlerJohn E. May, Jr.La

26、wrence V. McCallT. Don Michael*Lloyd A. Pete MorleyStig L. NilssonJohn L. RankineRonald H. ReimerGary S. RobinsonTerrance R. Whittemore*Member EmeritusAlso included are the following nonvoting IEEE Standards Board liaisons:Fernando AldanaSatish K. AggarwalJames BeallRichard B. EngelmanStanley Warsha

27、wAdam SickerIEEE Standards Project EditorivCLAUSE PAGE1. Purpose.12. Scope.13. References.24. Safety Practices .34.1 General Precautions . 34.2 Safety Aspects of Test Preparations. 34.3 Safety Aspects of Test Measurements . 45. Factors Effecting Grounding System Measurements.46. Preliminary Planning

28、 and Procedures .66.1 Distance to Current and Potential Test Electrodes. 66.2 Selection of Test-Conductor Routing and Test-Probe Locations . 66.3 Determining the Effect of Overhead-Ground-Wire Shielding on Test Current Distribution . 76.4 Estimating Grounding Grid Impedance . 76.5 Estimating Minimum

29、 Test Current . 76.6 Test Current Sources. 76.7 Estimating Test-Current Source Requirements. 86.8 Remote Rod Electrode Current Capacity. 86.9 Potential Input Impedance . 96.10 Determining Grounding System Connection Condition. 96.11 Establishing the Measurement Point on a Grounding System. 97. Earth

30、-Return Mutual Effects When Measuring Grounding-System Impedance .97.1 Introduction. 97.2 Measurement Error Due to Earth Mutual Resistances. 107.3 Measurement Error Due to AC Mutual Coupling. 107.4 Mutual Coupling to Potential Lead From Extended Ground Conductors . 128. Measurement of Low-Impedance

31、Grounding Systems by Test-Current Injection .128.1 Introduction. 128.2 Signal Generator and Power Amplifier Source. 138.3 Portable Power-Generator Source. 168.4 Power System Low-Voltage Source . 209. Measurement of Low-Impedance Grounding Systems by Power System Staged Faults .239.1 Introduction. 23

32、9.2 Fault Configurations . 249.3 Fault Initiation. 249.4 Current Measurements . 259.5 Potential Measurements . 25v9.6 Interference Reduction. 279.7 Calibration. 28CLAUSE PAGE10. Current Distribution in Extended Grounding Systems .3010.1 Introduction. 3010.2 Test Considerations. 3110.3 Analysis of Cu

33、rrent Distribution in a Grounding System (See B25 and B44). 3310.4 Induced Current in the Angled Overhead Ground Wire . 3710.5 Current Distribution During a Staged Fault Test (See B44) . 4111. Transfer Impedances to Communication or Control Cables.4912. Step, Touch, and Voltage-Profile Measurements .5112.1 General Requirements. 5112.2 Grid Safety Requirements. 5212.3 Footprint-Electrode Method.