国际电工委-员会 IEC60071-4 TR.pdf

TECHNICAL REPORT IEC TR 60071-4 First edition2004-06 Insulation co-ordination Part 4:Computational guide to insulation co-ordination and modelling of electrical networks Reference number IEC/TR 60071-4:2004(E)Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Publication numbering As from 1 January 1997 all IEC publications are issued with a designation in the 60000 series.For example,IEC 34-1 is now referred to as IEC 60034-1.Consolidated editions The IEC is now publishing consolidated versions of its publications.For example,edition numbers 1.0,1.1 and 1.2 refer,respectively,to the base publication,the base publication incorporating amendment 1 and the base publication incorporating amendments 1 and 2.Further information on IEC publications The technical content of IEC publications is kept under constant review by the IEC,thus ensuring that the content reflects current technology.Information relating to this publication,including its validity,is available in the IEC Catalogue of publications(see below)in addition to new editions,amendments and corrigenda.Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication,as well as the list of publications issued,is also available from the following:IEC Web Site(www.iec.ch)Catalogue of IEC publications The on-line catalogue on the IEC web site(www.iec.ch/searchpub)enables you to search by a variety of criteria including text searches,technical committees and date of publication.On-line information is also available on recently issued publications,withdrawn and replaced publications,as well as corrigenda.IEC Just Published This summary of recently issued publications(www.iec.ch/online_news/justpub)is also available by email.Please contact the Customer Service Centre(see below)for further information.Customer Service Centre If you have any questions regarding this publication or need further assistance,please contact the Customer Service Centre:Email:custserviec.ch Tel:+41 22 919 02 11 Fax:+41 22 919 03 00 Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TECHNICAL REPORT IECTR 60071-4 First edition2004-06 Insulation co-ordination Part 4:Computational guide to insulation co-ordination and modelling of electrical networks PRICE CODE IEC 2004 Copyright-all rights reserved No part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical,including photocopying and microfilm,without permission in writing from the publisher.International Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.iec.ch XE For price,see current catalogueCommission Electrotechnique InternationaleInternational Electrotechnical Commission Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 TR 60071-4 IEC:2004(E)CONTENTS FOREWORD.7 1 Scope and object.9 2 Normative references.9 3 Terms and definitions.9 4 List of symbols and acronyms.12 5 Types of overvoltages.12 6 Types of studies.13 6.1 Temporary overvoltages(TOV).14 6.2 Slow-front overvoltages(SFO).14 6.3 Fast-front overvoltages(FFO).15 6.4 Very-fast-front overvoltages(VFFO).15 7 Representation of network components and numerical considerations.15 7.1 General.15 7.2 Numerical considerations.15 7.3 Representation of overhead lines and underground cables.18 7.4 Representation of network components when computing temporary overvoltages.19 7.5 Representation of network components when computing slow-front overvoltages.25 7.6 Representation of network components when computing fast-front transients.30 7.7 Representation of network components when computing very-fast-front overvoltages.42 8 Temporary overvoltages analysis.44 8.1 General.44 8.2 Fast estimate of temporary overvoltages.45 8.3 Detailed calculation of temporary overvoltages 2,9.45 9 Slow-front overvoltages analysis.48 9.1 General.48 9.2 Fast methodology to conduct SFO studies.48 9.3 Method to be employed.49 9.4 Guideline to conduct detailed statistical methods.49 10 Fast-front overvoltages analysis.52 10.1 General.52 10.2 Guideline to apply statistical and semi-statistical methods.53 11 Very-fast-front overvoltage analysis.58 11.1 General.58 11.2 Goal of the studies to be performed.58 11.3 Origin and typology of VFFO.58 11.4 Guideline to perform studies.60 12 Test cases.60 12.1 General.60 12.2 Case 1:TOV on a large transmission system including long lines.60 12.3 Case 2(SFO)Energization of a 500 kV line.68 12.4 Case 3(FFO)Lightning protection of a 500 kV GIS substation.73 12.5 Case 4(VFFO)Simulation of transients in a 765 kV GIS 51.80 Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TR 60071-4 IEC:2004(E)3 Annex A(informative)Representation of overhead lines and underground cables.86 Annex B(informative)Arc modelling:the physics of the circuit-breaker.90 Annex C(informative)Probabilistic methods for computing lightning-related risk of failure of power system apparatus.93 Annex D(informative)Test case 5(TOV)Resonance between a line and a reactor in a 400/220 kV transmission system.99 Annex E(informative)Test case 6(SFO)Evaluation of the risk of failure of a gas-insulated line due to SFO.105 Annex F(informative)Test case 7(FFO)High-frequency arc extinction when switching a reactor.113 Bibliography.116 Figure 1 Types of overvoltages(excepted very-fast-front overvoltages).12 Figure 2 Damping resistor applied to an inductance.17 Figure 3 Damping resistor applied to a capacitance.17 Figure 4 Example of assumption for the steady-state calculation of a non-linear element.17 Figure 5 AC-voltage equivalent circuit.19 Figure 6 Dynamic source modelling.20 Figure 7 Linear network equivalent.21 Figure 8 Representation of load in 56.24 Figure 9 Representation of the synchronous machine.26 Figure 10 Diagram showing double distribution used for statistical switches.29 Figure 11 Multi-story transmission tower 16,H=l1+l2+l3+l4.31 Figure 12 Example of a corona branch model.33 Figure 13 Example of volt-time curve.34 Figure 14 Double ramp shape.38 Figure 15 CIGRE concave shape.39 Figure 16 Simplified model of earthing electrode.41 Figure 17 Example of a one-substation-deep network modelling.51 Figure 18 Example of a two-substation-deep network modelling.51 Figure 19 Application of statistical or semi-statistical methods.53 Figure 20 Application of the electro-geometric model.56 Figure 21 Limit function for the two random variables considered:the maximum value of the lightning current and the disruptive voltage.57 Figure 22 At the GIS-air interface:coupling between enclosure and earth(Z3),between overhead line and earth(Z2)and between bus conductor and enclosure(Z1)33.59 Figure 23 Single-line diagram of the test-case system.62 Figure 24 TOV at CHM7,LVD7 and CHE7 from system transient stability simulation.63 Figure 25 Generator frequencies at generating centres Nos.1,2 and 3 from system transient stability simulation.64 Figure 26 Block diagram of dynamic source model 55.65 Figure 27 TOV at LVD7 Electromagnetic transient simulation with 588 kV and 612 kV permanent surge arresters.66 Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 TR 60071-4 IEC:2004(E)Figure 28 TOV at CHM7 Electromagnetic transient simulation with 588 kV and 612 kV permanent surge arresters.67 Figure 29 TOV at LVD7 Electromagnetic transient simulation with 484 kV switched metal-oxide surge arresters.67 Figure 30 TOV at CHM7 Electromagnetic transient simulation with 484 kV switched metal-oxide surge arresters.67 Figure 31 Representation of the system.68 Figure 32 Auxiliary contact and main.70 Figure 33 An example of cumulative probability function of phase-to-earth overvoltages and of discharge probability of insulation in a configuration with trapped charges and insertion resistors.72 Figure 34 Number of failure for 1 000 operations versus the withstand voltage of the insulation.72 Figure 35 Schematic diagram of a 500 kV GIS substation intended for lightning studies.74 Figure 36 Waveshape of the lightning stroke current.75 Figure 37 Response surface approximation (failure and safe-state representation for one GIS section(node).77 Figure 38 Limit-state representation in the probability space of the physical variables Risk evaluation.79 Figure 39 Single-line diagram of a 765 kV GIS with a closing disconnector.81 Figure 40 Simulation scheme of the 765 kV GIS part involved in the transient phenomena of interest.81 Figure 41 4 ns ramp.84 Figure 42 Switch operation.85 Figure A.1 Pi-model.86 Figure A.2 Representation of the single conductor line.87 Figure B.1 SF6 circuit-breaker switching.91 Figure C.1 Example of a failure domain.96 Figure D.1 The line and the reactance are energized at the same time.99 Figure D.2 Energization configuration of the line minimizing the risk of temporary overvoltage.100 Figure D.3 Malfunction of a circuit-breaker pole during energization of a transformer.102 Figure D.4 Voltage in substation B phase A whose pole has not closed.103 Figure D.5 Voltage in substation B phase B whose pole closed correctly.103 Figure D.6 Voltage in substation B phase A where the breaker failed to close(configuration of Figure D.2).104 Figure E.1 Electric circuit used to perform closing overvoltage calculations.105 Figure E.2 Calculated overvoltage distribution Two estimated Gauss probability functions resulting from two different fitting criteria(the U2%and U10%guarantees a good fitting of the most dangerous overvoltages).107 Figure E.3 Example of switching overvoltage between phases A and B.and phase-to-earth(A and B).109 Figure E.4 Voltage distribution along the GIL(ER-energization ED-energization under single-phase fault ChPg-trapped charges).110 Figure F.1 Test circuit(Copyright1998 IEEE 48).113 Figure F.2 Terminal voltage and current of GCB model(Copyright 1998 IEEE 48).113 Figure F.3 Measured arc parameter(Copyright 1998 IEEE 48).114 Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TR 60071-4 IEC:2004(E)5 Figure F.4 Circuit used for simulation.114 Figure F.5 Comparison between measured and calculated results(Copyright 1998 IEEE 48).115 Table 1 Classes and shapes of overvoltages Standard voltage shapes and standard withstand tests.13 Table 2 Correspondence between events and most critical types of overvoltages generated.14 Table 3 Application and limitation of current overhead line and underground cable models.18 Table 4 Values of U0,k,DE for different configurations proposed by 59.35 Table 5 Minimum transformer capacitance to earth taken from 44.37 Table 6 Typical transformer capacitance to earth taken from 28.37 Table 7 Circuit-breaker capacitance to earth taken from 28.37 Table 8 Representation of the first negative downward strokes.40 Table 9 Time to half-value of the first negative downward strokes.40 Table 10 Representation of the negative downward subsequent strokes.40 Table 11 Time to half-value of negative downward subsequent strokes.40 Table 12 Representation of components in VFFO studies.43 Table 13 Types of approach to perform FFO studies.52 Table 14 Source side parameters.69 Table 15 Characteristics of the surge arresters.69 Table 16 Characteristics of the shunt reactor.69 Table 17 Capacitance of circuit-breaker.70 Table 18 Trapped charges.70 Table 19 System configurations.71 Table 20 Recorded overvoltages.71 Table 21 Number of failures for 1 000 operations.72 Table 22 Modelling of the system.76 Table 23 Data used for the application of the EGM.76 Table 24 Crest-current distribution.77 Table 25 Number of strikes terminating on the different sections of the two incoming overhead transmission lines.77 Table 26 Parameters of GIS disruptive voltage distribution and lightning crest-current distribution.78 Table 27 FORM risk estimations(tower footing resistance=10).79 Table 28 Failure rate estimation for the GIS11.80 Table 29 Representation of GIS components Data of the 765 kV GIS.82 Table D.1 Line parameters.100 Table D.2 400/220/33 kV transformer.101 Table D.3 220/13,8 kV transformer.101 Table D.4 Points of current and flux of 400/220/33 kV transformer.101 Table D.5 Points of current and flux of 220/13,8 kV transformer.101 Table D.6 Points of current and flux of 400 kV/150 MVAr.102 Table E.1 Parameters of the power supply.105 Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 TR 60071-4 IEC:2004(E)Table E.2 Standard deviation and U50M for different lengths (SIWV=1 050 kV).108 Table E.3 Standard deviation and U50M for different lengths (SIWV=950 kV).108 Table E.4 Standard deviation and U50M for different lengths (SIWV=850 kV).108 Table E.5 Statistical overvoltages U2%and U10%for every considered configuration.110 Table E.6 Risks for every considered configuration.111 Table E.7 Number of dielectric breakdowns over 20 000 operations for every configuration.112 Copyright International Electrotechnical Commission Provided by IHS under license with IECNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TR 60071-4 IEC:2004(E)7 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ INSULATION CO-ORDINATION Part 4:Computational guide to insulation co-ordination and modelling of electrical networks FOREWORD 1)The International Electrotechnical Commission(IEC)is a worldwide organization for standardization comprising all national electrotechnical committees(IEC National Committees).The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields.To this end and in addition to other activities,IEC publishes International Standards,Technical Specifications,Technical Reports,Publicly Available Specifications(PAS)and Guides(hereafter referred to as“IEC Publication(s)”).Their preparation is entrusted to technical committees;any IEC National Committee interested in the subject dealt with may participate in this preparatory work.International,governmental and non-governmental organizations liaising with the IEC also participate in this preparation.IEC collaborates closely with the International Organization for Standardization(ISO)in accordance with conditions determined by