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IEC TR 60909-4:2021

(Main)

Short-circuit currents in three-phase AC systems - Part 4: Examples for the calculation of short-circuit currents

Short-circuit currents in three-phase AC systems - Part 4: Examples for the calculation of short-circuit currents

IEC TR 60909-4:2021 which is a Technical Report, is intended to give help for the application of IEC 60909-0 for the calculation of short-circuit currents in 50 Hz or 60 Hz three-phase AC systems.
This document does not include additional requirements but gives support for the modelling of electrical equipment in the positive-sequence, the negative-sequence and the zero-sequence system (Clause 4), the practical execution of calculations in a low-voltage system (Clause 5), a medium-voltage system with asynchronous motors (Clause 6) and a power station unit with its auxiliary network feeding a large number of medium-voltage asynchronous motors and low-voltage motor groups (Clause 7).
The three examples given in Clauses 5, 6 and 7 are similar to those given in IEC TR 60909-4:2000 but they are revised in accordance with IEC 60909-0, which replaces it. The example given in Clause 8 is new and mirrors the introduction of the new 6.8 of IEC 60909-0:2016.
Clause 9 gives the circuit diagram and the data of a test network and the results for a calculation carried out in accordance with IEC 60909-0, to offer the possibility for a comparison between the results found with a digital program for the calculation of short-circuit currents and the given results for and in a high-voltage network with power station units, generators, asynchronous motors and lines in four different voltage levels 380 kV, 110 kV, 30 kV and 10 kV.
This second edition cancels and replaces the first edition published in 2000. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) adaption to IEC 60909-0:2016;
b) addition of an example for the calculation of short-circuit currents of wind power station units;
c) correction of errors.

General Information

Status
Published
Publication Date
23-Jun-2021
ICS
17.220.01 - Electricity. Magnetism. General aspects
29.240.20 - Power transmission and distribution lines
Technical Committee
TC 73 - Short-circuit currents
Drafting Committee
MT 1 - TC 73/MT 1
Current Stage
PPUB - Publication issued
Start Date
20-May-2021
Completion Date
24-Jun-2021
Ref Project

Relations

Revises
IEC TR 60909-4:2000 - Short-circuit currents in three-phase a.c. systems - Part 4: Examples for the calculation of short-circuit currents
Effective Date
05-Sep-2023

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IEC TR 60909-4:2021 - Short-circuit currents in three-phase AC systems - Part 4: Examples for the calculation of short-circuit currentsIEC TR 60909-4:2021 - Short-circuit currents in three-phase AC systems - Part 4: Examples for the calculation of short-circuit currents
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Technical report
IEC TR 60909-4:2021 - Short-circuit currents in three-phase AC systems - Part 4: Examples for the calculation of short-circuit currents
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IEC TR 60909-4
®

Edition 2.0 2021-06
TECHNICAL
REPORT

colour
inside


Short-circuit currents in three-phase AC systems –
Part 4: Examples for the calculation of short-circuit currents
IEC TR 60909-4:2021-06(en)

---------------------- Page: 1 ----------------------
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IEC TR 60909-4

®


Edition 2.0 2021-06




TECHNICAL



REPORT








colour

inside










Short-circuit currents in three-phase AC systems –

Part 4: Examples for the calculation of short-circuit currents


























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ICS 17.220.01; 29.240.20 ISBN 978-2-8322-9932-6




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---------------------- Page: 3 ----------------------
– 2 – IEC TR 60909-4:2021 © IEC 2021
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions, symbols and indices, and formulae . 8
4 Positive-sequence, negative-sequence and zero-sequence impedances of
electrical equipment . 9
4.1 General . 9
4.2 Overhead lines, cables and short-circuit current-limiting reactors . 9
4.3 Transformers . 10
4.3.1 General . 10
4.3.2 Example . 15
4.4 Generators and power station units . 17
4.4.1 General . 17
4.4.2 Example .
...

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