三相交流系统中的短路电流 第0部分：电流计算

1.3 Definitions

For the purposes of this part of IEC 60909, the definitions given in IEC 60050(131) and the following definitions apply.

1.3.1 short circuit

accidental or intentional conductive path between two or more conductive parts forcing the electric potential differences between these conductive parts to be equal or close to zero

1.3.1.1 line-to-line short circuit

accidental or intentional conductive path between two or more line conductors with or without earth connection

1.3.1.2 line-to-earth short circuit

accidental or intentional conductive path in a solidly earthed neutral system or an impedance earthed neutral system between a line conductor and local earth

1.3.2 short-circuit current

over-current resulting from a short circuit in an electric system

NOTE It is necessary to distinguish between the short-circuit current at the short-circuit location and partial short-circuit currents in the network branches (see figure 3) at any point of the network.

1.3.3 prospective (available) short-circuit current

current that would flow if the short circuit were replaced by an ideal connection of negligible impedance without any change of the supply (see note of 1.1)

1.3.4 symmetrical short-circuit current

r.m.s. value of the a.c. symmetrical component of a prospective (available) short-circuit current (see 1.3.3), the aperiodic component of current, if any, being neglected

1.3.5 initial symmetrical short-circuit current I_k

r.m.s. value of the a.c. symmetrical component of a prospective (available) short-circuit current (see 1.3.3), applicable at the instant of short circuit if the impedance remains at zero-time value (see figures 1 and 2)

1.3.6 initial symmetrical short-circuit power S_k

fictitious value determined as a product of the initial symmetrical short-circuit current I_k (see 1.3.5), the nominal system voltage U_n (see 1.3.13) and the factor √3: S_k = √3 U_n I_k

NOTE The initial symmetrical short-circuit power S_k is not used for the calculation procedure in this standard. If S_k is used in spite of this in connection with short-circuit calculations, for instance to calculate the internal impedance of a network feeder at the connection point Q, then the definition given should be used in the following form: S_kQ = √3 U_nQ I_kQ or Z_Q = cU_nQ² / S_kQ.

1.3.7 decaying (aperiodic) component i_d.c. of short-circuit current

mean value between the top and bottom envelope of a short-circuit current decaying from an initial value to zero according to figures 1 and 2

1.3.8 peak short-circuit current i_p

maximum possible instantaneous value of the prospective (available) short-circuit current (see figures 1 and 2)

NOTE The magnitude of the peak short-circuit current varies in accordance with the moment at which the short circuit occurs. The calculation of the three-phase peak short-circuit current i_p applies to the line conductor and to the instant at which the greatest possible short-circuit current exists. Sequential short circuits are not considered.

1.3.9 symmetrical short-circuit breaking current I_b

r.m.s. value of an integral cycle of the symmetrical a.c. component of the prospective short-circuit current at the instant of contact separation of the first pole to open of a switching device

1.3.10 steady-state short-circuit current I_k

r.m.s. value of the short-circuit current which remains after the decay of the transient phenomena (see figures 1 and 2)

1) To be published.

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Révision de la présente publication

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En ce qui concerne la terminologie générale, le lecteur se reportera à la Publication 50 de la CEI : Vocabulaire Electrotechnique International (VEI), qui est établie sous forme de chapitres séparés traitant chacun d'un sujet défini, l'Index général étant publié séparément. Des détails complets sur le VEI peuvent être obtenus sur demande.

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• la Publication 27 de la CEI : Symboles littéraux à utiliser en électrotechnique ;
• la Publication 617 de la CEI : Symboles graphiques pour schémas.

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For graphical symbols, and letter symbols and signs approved by the IEC for general use, readers are referred to :

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• IEC Publication 617 : Graphical symbols for diagrams.

The symbols and signs contained in the present publication have either been taken from IEC Publications 27 or 617, or have been specifically approved for the purpose of this publication.

IEC publications prepared by the same Technical Committee

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2

NORME INTERNATIONALE INTERNATIONAL STANDARD МЕЖДУНАРОДНЫЙ СТАНДАРТ

NORME INTERNATIONALE INTERNATIONAL STANDARD МЕЖДУНАРОДНЫЙ СТАНДАРТ

CEI IEC 50(426) Première édition First edition 1990-10 Vocabulaire Electrotechnique International Chapitre 426 : Matériel électrique pour atmosphères explosives International Electrotechnical Vocabulary Chapter 426 : Electrical apparatus for explosive atmospheres Международный Электротехнический Словарь Глава 426 : Электрооборудование для взрывоопасных сред © CEI 1990 Droits de reproduction réservés - Copyright - all rights reserved - Право издания охраняется законом Aucune partie de cette publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit de l'éditeur. 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. Запрещается Без письменного разрешения издателя воспроизведение или копирование этой публикации или ее части в любой форме или любыми средствами — электронными или механическими, включая фотоконю и микрофильм. Bureau central de la Commission Electrotechnique Internationale 3, rue de Varembé Genève Suisse Commission Electrotechnique Internationale International Electrotechnical Commission Международная Электротехническая Комиссия Code prix Price code Код цены S Pour prix, voir catalogue en vigueur For price, see current catalogue Цена указана в действующем каталоге 3

50(715) © IEC:1996

CONTENTS

FOREWORD	VII
PREFACE	VII
Sections
715-01	Basic terms	1
715-02	Resources	10
715-03	Calls	17
715-04	Times and delays	22
715-05	Traffic	24
715-06	Circuit groups	32
715-07	Traffic engineering	34
715-08	Networks	41
715-09	Circuit switched networks	46
715-10	Message switched networks	51
715-11	Packet switched networks	52
Index	53

:current

Foreword

This document (EN 10216-3:2002) has been prepared by Technical Committee EC/TC 29, "Steel tubes and fittings for steel tubes", the secretariat of which is held by UNI.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2002, and conflicting national standards shall be withdrawn at the latest by November 2002.

This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document.

Other Parts of EN 10216 are:

Part 1:	Non-alloy steel tubes with specified room temperature properties
Part 2:	Non-alloy and alloy steel tubes with specified elevated temperature properties
Part 4:	Non-alloy and alloy steel tubes with specified low temperature properties
Part 5:	Stainless steel tubes

Another European Standard series covering tubes for pressure purposes is:

EN 10217:

Welded steel tubes for pressure purposes

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

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1 Scope

This Part of EN 10216 specifies the technical delivery conditions in two test categories for seamless tubes of circular cross section, made of weldable alloyed fine grained steel.

2 Normative references

This European Standard incorporates by date or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For date references, subsequent amendments to or revisions of, any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments).

The requirements of this European Standard rule when they differ from those in the standards and documents referred to below:

EN 10002-1, Metallic materials - Tensile testing - Part 1: Method of test (at ambient temperature).

EN 10002-5, Metallic materials - Tensile testing - Part 5: Method of testing (at elevated temperature).

EN 10020, Definitions and classification of grades of steel.

EN 10021, General technical delivery requirements for steel and iron products.

EN 10045-1, Metallic materials - Charpy impact test - Part 1: Test method.

EN 10052, Vocabulary of heat treatment terms for ferrous products.

EN 10204, Metallic products - Types of inspection documents.

EN 10027-1, Designation systems for steels - Part 1: Steel names, principle symbols.

EN 10027-2, Designation systems for steels Part 2: Numerical systems.

ENV 10220, Seamless and welded steel tubes - Dimensions and masses per unit length

EN 10233, Metallic materials - Tubes - Flattening test.

EN 10234, Metallic materials - Tubes - Drift expanding test.

EN 10236, Metallic materials - Tubes - Ring expanding test.

EN 10237, Metallic materials - Tubes - Ring tensile test.

EN 10246-1, Non-Destructive Testing of steel tubes Part 1: Automatic electromagnetic testing of seamless and welded (except submerged arc welded) ferromagnetic steel tubes for verification of hydraulic leak-tightness.

EN 10246-5, Non-Destructive Testing of steel tubes - Part 5: Automatic full peripheral magnetic transducer/flux leakage testing of seamless and welded (except submerged arc-welded) ferromagnetic steel tubes for the detection of longitudinal imperfections.

EN 10246-6, Non-Destructive Testing of steel tubes - Part 6: Automatic full peripheral ultrasonic testing of seamless steel tubes for the detection of transverse imperfections.

EN 10246-7, Non-Destructive Testing of steel tubes - Part 7: Automatic full peripheral ultrasonic testing of seamless and welded (except submerged arc welded) steel tubes for the detection of longitudinal imperfections.

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