高压开关设备及开关装置（最高52kV）

8.1.6 I_s-limiter – fastest switching device in the world

The increasing requirements for energy throughout the world demand higher rated or supplementary transformers and generators and tighter integration of the supply systems. This can also result in the permissible short-circuit currents of the equipment being exceeded and the equipment being dynamically or thermally destroyed.

It is often not technically possible or not economical for the user to replace switchboards and cable connections with new equipment with increased short-circuit current capability. The implementation of I_s-limiters when expanding existing installations and constructing new installations reduces short-circuit currents and costs.

A circuit-breaker does not provide protection against impermissibly high peak short-circuit currents, because it is too slow. Only the I_s-limiter is capable of detecting and limiting a short-circuit current in the initial rise, i.e. in less than one millisecond. The maximum instantaneous current value that occurs remains well below the peak value of the short-circuit current of the system.

Typical I_s-limiter applications (Fig. 8-10):

• in couplings,
• in coupling the public system with a private supply,
• parallel to reactor coils,
• (avoids copper losses and voltage drop at the reactor coils)
• in transformer or generator feeders,
• in outgoing feeders.

The I_s-limiter is a current-limiting switching device, which detects and limits the short-circuit current in the initial rise. The short-circuit current through the I_s-limiter is limited so quickly that it does not contribute in any way to the peak value of the short-circuit current at the fault site.

Fig. 8-8

Short-circuit breaking with I_s limiters

a) Current path

i_o Total current without I_s limiter

i_m Total current with I_s limiter

b) Basic layout

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2 Scope

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EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 10216-3

May 2002

ICS 23.040.10; 77.140.75

English version

Seamless steel tubes for pressure purposes –
Technical delivery conditions

Part 3: Alloy fine grain steel tubes

Tubes sans soudure en acier pour service sous pression – Conditions techniques de livraison – Partie 3: Tubes en acier allié à grain fin

Nahtlose Stahlrohre für Druckbeanspruchungen – Technische Lieferbedingungen – Teil 3: Rohre aus legierten Feinkornbaustählen

This European Standard was approved by CEN on 2002-04-25.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member.

The European Standards exist in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom.

CEN

European Committee for Standardization

Comité Européen de Normalisation

Europäisches Komitee für Normung

Management Centre: rue de Stassart 36, B-1050 Brussels

© 2002. CEN – All rights of exploitation in any form and by any means reserved worldwide for CEN national members.

Ref. No. EN 10216-3 : 2002 E

Contents

Section	Page
Foreword	3
Introduction	4
1 Scope	4
2 Normative references	5
3 Definitions	5
3.1 DN	5
3.2 PN	5
4 Designations	6
4.1 Range of PN designations	6
4.2 Range of DN (nominal sizes)	6
4.3 Gasket types	6
4.4 Information to be supplied by the purchaser	6
5 Gasket designs	6
6 Gasket types	7
7 Dimensions	7
8 Marking	10
Annex A (informative) Information to be supplied by the purchaser	10
Annex B (informative) A-deviation	11

: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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