1、FORM CD(IEC)2002-08-08 77A/517/CDCOMMITTEE DRAFT(CD)IEC/TC or SC:SC 77A Project number IEC 61000-2-14,TR,Ed.1 Title of TC/SC:EMC:Low frequency phenomena Date of circulation 2005-11-04 Closing date for comments 2006-02-10 Also of interest to the following committees 8,37A,64,109 Supersedes document F
2、unctions concerned:Safety EMC Environment Quality assurance Secretary:Mrs.N.BAUMIER-DUPHIL(France)Email:nathalie.baumieredf.fr THIS DOCUMENT IS STILL UNDER STUDY AND SUBJECT TO CHANGE.IT SHOULD NOT BE USED FOR REFERENCE PURPOSES.RECIPIENTS OF THIS DOCUMENT ARE INVITED TO SUBMIT,WITH THEIR COMMENTS,N
3、OTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION.Title:IEC 61000-2-14,TR,Ed.1:Electromagnetic compatibility(EMC)-Part 2-14:Overvoltages on public electricity distribution networks (Titre):CEI 61000-2-14,TR,Ed.1:Compatibilit electromagntique(CE
4、M)-Partie 2-14:Surtensions sur les rseaux publics de distribution dlectricit Introductory note It has come to the attention of IEC SC77A that there is a need for complementary information to accompany 61000-2-8(voltage dips and short interruptions),explaining the phenomenon of overvoltages on public
5、 networks.The publication of a Technical Report on overvoltages was decided during IEC SC77A Plenary Meeting in Cape Town(18th 19th October 2005).The purpose of this TR is to ensure that this important category of electromagnetic disturbance is included in the description of the electromagnetic envi
6、ronment in Part 2 of IEC 61000.For that purpose,a brief description is provided of the various overvoltages and their causes and effects.It has to be noted that other publications such as IEC/TR 62066 already cover the scope of that TR either partly or with a different perspective.Attention should b
7、e paid to the consistency with those publications.Copyright 2005 International Electrotechnical Commission,IEC.All rights reserved.It is permitted to download this electronic file,to make a copy and to print out the content for the sole purpose of preparing National Committee positions.You may not c
8、opy or mirror the file or printed version of the document,or any part of it,for any other purpose without permission in writing from IEC.2 77A/517/CD CONTENTS 1 Scope.7 2 Definitions.8 3 Description of overvoltages.10 3.1 General.10 3.2 External overvoltages.10 3.3 Internal overvoltages.10 3.4 Overv
9、oltage waveshape.10 4 Long duration overvoltages.11 4.1 Sustained earth faults.11 4.2 Broken neutral on LV network.11 4.3 Maloperation of voltage regulating equipment.12 4.4 Overvoltages due to voltage unbalances.12 4.5 Dispersed generation.13 5 Short duration overvoltages.14 5.1 Earth faults.14 5.2
10、 Load rejection(sudden load loss).15 5.3 Self-excitation.16 5.4 Resonance and ferro-resonance.16 5.4.1 Resonance.16 5.4.2 Ferroresonance.17 6 Very short duration overvoltages(transients).18 6.1 General description.18 6.2 Lightning.18 6.2.1 General discussion on lightning.18 6.2.2 Direct lightning st
11、roke.19 6.2.3 Indirect or Induced Lightning Stroke.19 6.2.4 Lightning back flashover.19 6.2.5 Lightning strokes on structures connected to the electricity network.20 6.3 Switching.20 6.3.1 Fault switching.20 6.3.2 Routine switching.20 6.3.3 Shunt capacitor and cable switching.21 6.3.4 Commutation Os
12、cillations.24 6.3.5 Switching of shunt reactors.24 6.3.6 Switching of transformers.25 6.3.7 Controlled switching of circuit breakers.25 6.4 Summary of surge duration and cause.26 7 Effects of overvoltages on equipment.27 7.1 General considerations.27 7.2 Reduction in life of filament lamps.28 7.3 Ef
13、fect of overvoltages on IT equipment.29 8 Case Studies.29 3 77A/517/CD 8.1 General.29 8.2 Switching of LV Power Factor Correction Capacitor.29 8.3 Metal Fusion Furnace.30 8.4 Switching of MV Power Factor Correction Capacitor.32 8.4.1 Circumstances.32 8.4.2 Causes.32 8.4.3 Solution.33 8.5 DC traction
14、 system.33 8.5.1 Circumstances.33 8.5.2 Causes.33 8.5.3 Solutions.34 8.6 Loadswitching.34 8.6.1 Situation.34 8.6.2 Solution.34 9 Protection against the effects of overvoltages.36 9.1 General considerations.36 9.2 Point on wave switching.36 9.3 Arcing Horns and Spark Gaps.37 9.3.1 Arcing Horns.37 9.3
15、.2 Spark Gaps.37 9.4 Overvoltage protection relays.38 9.5 Snubbers(high frequency RC filter).38 9.6 Uninterruptable Power Supply(UPS)Systems.39 9.7 Surge Protection Device(SPD).39 9.7.1 SPDs for LV Applications.40 9.7.2 SPDs for MV and HV Applications-fitted at source.41 10 Conclusions.42 11 Recomme
16、ndations.42 Figure 1:Lightning Impulse Test Voltage Characteristic(taken from IEC 60060-1).10 Figure 2:Broken Neutral on LV Network.12 Figure 3:Effect of distributed generation on network voltage.14 Figure 4:Line Neutral temporary overvoltage on healthy phase for single phase line earth fault.15 Figure 5:Typical transient overvoltage when energizing a capacitor bank.22 Figure 6:Notching caused by power electronics switching.24 Figure 7:ITI(CBEMA)Curve for equipment connected to 120V 60Hz systems
