SIST HD 533 S1:1998
(Main)Short-circuit current calculation in three-phase a.c. systems
Short-circuit current calculation in three-phase a.c. systems
This standard is applicable to the calculation of short-circuit currents: -in low-voltage three-phase a.c. systems, -in high-voltage three-phase a.c. systems with nominal voltages up to 230 kV operating at nominal frequency (50 Hz or 60 Hz). This standardized procedure is given in such a form as to facilitate as far as possible its use by non-specialist engineers.
Berechnung von Kurzschlußströmen in Drehstromnetzen
Calcul des courants de court-circuit dans les réseaux triphasés à courant alternatif
S'applique au calcul des courants de court-circuit: - dans les réseaux triphasés basse tension à courant alternatif, - dans les réseaux triphasés haute tension à courant alternatif de tensions nominales jusqu'à 230 kV, fonctionnant à fréquence nominale (50 Hz ou 60 Hz). Dans la mesure du possible, cette procédure normalisée est présentée de façon à pouvoir être utilisée par des ingénieurs non spécialisés.
Short-circuit current calculation in three-phase a.c. systems (IEC 60909:1988, modified)
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IEC 60909-0:2016 is applicable to the calculation of short-circuit currents in low-voltage three-phase AC systems, and in high-voltage three-phase AC systems, operating at a nominal frequency of 50 Hz or 60 Hz. It establishes a general, practicable and concise procedure leading to results which are generally of acceptable accuracy and deals with the calculation of short-circuit currents in the case of balanced or unbalanced short circuits. This second edition cancels and replaces the first edition published in 2001. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- contribution of windpower station units to the short-circuit current;
- contribution of power station units with ful size converters to the short-circuit current;
- new document structure.
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This part of IEC 60865 is applicable to the mechanical and thermal effects of short-circuit currents. It contains procedures for the calculation of - the electromagnetic effect on rigid conductors and flexible conductors, - the thermal effect on bare conductors. For cables and insulated conductors, reference is made, for example, to IEC 60949 and IEC 60986. For the electromagnetic and thermal effects in d.c. auxiliary installations of power plants and substations reference is made to IEC 61660-2. Only a.c. systems are dealt with in this standard. The following points should, in particular, be noted: a) The calculation of short-circuit currents should be based on IEC 60909. For the determination of the greatest possible short-circuit current, additional information from other IEC standards may be referred to, e.g. details about the underlying circuitry of the calculation or details about current-limiting devices, if this leads to a reduction of the mechanical stress. b) Short-circuit duration used in this standard depends on the protection concept and should be considered in that sense. c) These standardized procedures are adjusted to practical requirements and contain simplifications which are conservative. Testing or more detailed methods of calculation or both may be used. d) In Clause 5 of this standard, for arrangements with rigid conductors, only the stresses caused by short-circuit currents are calculated. Furthermore, other stresses can exist, e.g. caused by dead-load, wind, ice, operating forces or earthquakes. The combination of these loads with the short-circuit loading should be part of an agreement and/or be given by standards, e.g. erection-codes. The tensile forces in arrangements with flexible conductors include the effects of deadload. With respect to the combination of other loads the considerations given above are valid. e) The calculated loads are design loads and should be used as exceptional loads without any additional partial safety factor according to installation codes of, for example, IEC 61936-1.
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This part of IEC 60909 specifies procedures for calculation of the prospective short-circuit currents with an unbalanced short circuit in high-voltage three-phase a.c. systems operating at nominal frequency 50 Hz or 60 Hz, i. e.: a) currents during two separate simultaneous line-to-earth short circuits in isolated neutral or resonant earthed neutral systems; b) partial short-circuit currents flowing through earth in case of single line-to-earth short circuit in solidly earthed or low-impedance earthed neutral systems. The currents calculated by these procedures are used when determining induced voltages or touch or step voltages and rise of earth potential at a station (power station or substation) and the towers of overhead lines. Procedures are given for the calculation of reduction factors of overhead lines with one or two earth wires. The standard does not cover: a) short-circuit currents deliberately created under controlled conditions as in short circuit testing stations, or b) short-circuit currents in the electrical installations on board ships or aeroplanes, or c) single line-to-earth fault currents in isolated or resonant earthed systems. The object of this standard is to establish practical and concise procedures for the calculation of line-to-earth short-circuit currents during two separate simultaneous line-to-earth short circuits and partial short-circuit currents through earth, earth wires of overhead lines and sheaths or shields of cables leading to conservative results with sufficient accuracy. For this purpose, the short-circuit currents are determined by considering an equivalent voltage source at the short-circuit location with all other voltage sources set to zero. Resistances of earth grids in stations or footing resistances of overhead line towers are neglected, when calculating the short-circuit currents at the short-circuit location. This standard is an addition to IEC 60909-0. General definitions, symbols and calculation assumptions refer to that publication. Special items only are defined or specified in this standard. The calculation of the short-circuit currents based on the rated data of the electrical equipment and the topological arrangement of the system has the advantage of being possible both for existing systems and for systems at the planning stage. The procedure is suitable for determination by manual methods or digital computation. This does not exclude the use of special methods, for example the super-position method, adjusted to particular circumstances, if they give at least the same precision. As stated in IEC 60909-0, short-circuit currents and their parameters may also be determined by system tests.
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Describes method for calculating short-circuit currents in d.c. auxilliary systems in power plants and substations, which can be equipped with the following equipment, acting as short-circuit current sources: - rectifiers in three-phase a.c. bridge connection for 50 Hz; - stationary lead-acid batteries; - smoothing capacitors; - d.c. motors with independent excitation Provides a generally applicable method of calculation which produces results of sufficient accuracy on the conservative side.
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Describes a method for calculation of the mechanical and thermal effects on rigid conductors caused by short-circuit currents in d.c. auxilliary installations in power plants and substations, as described in EN 61660-1. Provides a method which has wide application and which gives results of sufficient accuracy. The calculation method is based on substitute functions, which cause approximately the same maximum stresses in the conductors and the same forces on the supports as the actual electromagnetic force.
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This part of IEC 60404 is applicable to surface insulation coatings on electrical steel strip and
sheet classified in IEC 60404-1-1.
This document defines the general principles and technical details of the tests for the
assessment of the thermal endurance of surface insulation coatings on electrical steel strip and
sheet.
The assessment is made by evaluating the change of a specified property of the surface
insulation coating due to a heat treatment at a specified temperature up to 850 °C for a specified
duration time up to 2 500 h. The specified property is measured at an ambient temperature of
(23 ± 5) °C both without heat treatment and after heat treatment.
This document is applicable to the following properties of surface insulation coatings:
– adhesion;
– surface insulation resistance;
– stacking factor.
This document is not applicable to other properties of surface insulation coatings, e.g. welding
properties, or to other effects, e.g. discoloration and off-gassing, which can be caused by
exposure to elevated temperatures.
NOTE Some of the tests take a very long time to perform and therefore they are often not appropriate for acceptance
tests of material supplied on a specific order.
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IEC 80000-6:2022 gives names, symbols, and definitions for quantities and units of electromagnetism. Where appropriate, conversion factors are also given. International Standard IEC 80000-6 has been prepared by IEC technical committee 25: Quantities and units, and their letter symbols in close cooperation with ISO/TC 12, Quantities and units.
This standard is based on classical electromagnetism, i.e. mainly Maxwell’s equations. No reference is made to quantum field theories.
IEC 80000-6:2022 cancels and replaces the first edition published in 2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
1) With the new definitions in SI, some previously exact values for quantities now must be determined experimentally while other quantities are given as exact values;
2) Item 6-2.2, elementary charge added;
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5) Editorial alignment to other parts of the IEC and ISO 80000 series.
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This part of IEC 60404 is applicable to electrical steel strip and sheet insulated by coating on one or both surfaces.
The object of this document is to define the general principles and technical details of the measurement of the surface insulation resistance of electrical steel strip and sheet.
NOTE This test is suitable for manufacturing and quality control in the application of insulation coatings.
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This part of IEC 62822, which is a product family standard, applies to equipment for
resistance welding, arc welding and allied processes designed for occupational use by
professionals and for use by laymen.
NOTE 1 Typical allied processes are resistance hard and soft soldering, resistance heating by means comparable
to resistance welding equipment, electric arc cutting and arc spraying.
The frequency range covered is 0 Hz to 300 GHz.
This product family standard specifies assessment methods and criteria to evaluate
electromagnetic field (EMF) emissions of electric welding equipment with regard to national
and international requirements for human exposure to EMF.
NOTE 2 Magnetic fields generated by the operation of welding equipment and the resulting non-thermal effects
are the main assessment concern.
This product family standard does not define requirements and methods for workplace
assessment regarding the risks arising from electromagnetic fields. However, the EMF
exposure data that results from the application of this product family standard can be used to
assist in workplace assessment.
NOTE 3 The equipment manufacturer is unaware of the overall exposure environment in which the equipment will
be used (e.g. multiple sources) and is not responsible for all requirements for workplace assessment (e.g.
information and training of workers, design and layout of the workplace).
Other standards may apply to products covered by this standard. In particular this standard
cannot be used to demonstrate electromagnetic compatibility with other equipment. It does
not specify any product safety requirements other than those specifically related to human
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- 08-Oct-2018
- 17.220.01
- 25.160.30
- 2013/35/EU
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