IEC TR 60909-1-2002 PDF

Full title and description

St IEC TR 60909-1-2002 — Short-circuit currents in three-phase a.c. systems — Part 1: Factors for the calculation of short-circuit currents according to IEC 60909-0. This Technical Report explains the origin, derivation and application of the correction factors and coefficients used when applying the standardized calculation procedures of IEC 60909-0 for three-phase AC short-circuit current calculations.

Abstract

This technical report provides the background, justification and numerical factors (tables, curves and formulas) that are applied alongside IEC 60909-0 to determine initial symmetrical, peak and steady-state short-circuit currents in three-phase AC systems. It is intended as a supporting document to improve precision and consistency of fault current calculations across power systems and to give guidance on the derivation and use of factors for generators, transformers, lines and other network elements.

General information

• Status: Technical Report (main); listed as active / stable to its published stability date.
• Publication date: 31 July 2002.
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 17.220.01; 29.240.20.
• Edition / version: Edition 2.0.
• Number of pages: 161.

Key publication metadata above is taken from the IEC bibliographic entry for IEC TR 60909-1:2002.

Scope

The report applies to calculation of short-circuit currents in three-phase AC systems and is to be read in conjunction with IEC 60909-0 (Part 0: Calculation of currents). It documents the factors, limiting values and application rules (for example generator and transformer correction factors, voltage tolerance and X/R-related peak factors) needed to apply the standard calculation models in practice for low-, medium- and high-voltage networks. The TR does not change the calculation procedures of IEC 60909-0 but provides the origin and recommended numerical values of the factors used.

Key topics and requirements

• Derivation and justification of correction factors (λ, κ and other symbols) used with IEC 60909-0.
• Voltage tolerance and voltage factor values for greatest and smallest short-circuit currents.
• Generator and transformer excitation and subtransient/synchronous contribution factors (λmax, λmin).
• X/R ratio considerations and methods for estimating peak (ip) and initial symmetrical (Ik'') currents.
• Tables, curves and worked numerical factors for practical application in systems of different voltage levels.
• Guidance on using the TR together with IEC 60909-0 and other parts of the 60909 series for consistent fault studies.

Typical use and users

Used by power-system and protection engineers, utilities, consulting electrical engineers, switchgear and transformer manufacturers, software vendors producing short-circuit calculation tools, and standards committees. Practically it is applied during network planning, protection coordination studies, equipment selection and verification of breaking and making capacities.

Related standards

This Technical Report is part of the IEC 60909 set: see IEC 60909-0 (Part 0 — Calculation of currents) and related parts such as Part 2 (data of electrical equipment), Part 3 (earth-fault/partial currents) and Part 4 (examples). The TR is intended to be used in conjunction with IEC 60909-0 and complements the calculation guidance given there. For later revisions of Part 0 and other parts, users should consult the current editions of each part when performing new studies.

Keywords

short-circuit currents; three-phase; IEC 60909; calculation factors; λ factor; κ factor; X/R ratio; fault current; peak current; initial symmetrical current; technical report.

FAQ

Q: What is this standard?

A: IEC TR 60909-1:2002 is a Technical Report that documents the origin, derivation and recommended numerical factors used when applying the IEC 60909 fault-current calculation procedures (Part 0). It does not change the calculation rules in Part 0 but provides supporting material and numerical guidance.

Q: What does it cover?

A: It covers correction and application factors (voltage factors, generator/transformer excitation factors, X/R-related peak factors, etc.), plus curves, tables and explanatory material for applying the IEC 60909-0 calculation models to real networks.

Q: Who typically uses it?

A: Power-system planners, protection engineers, utilities, equipment manufacturers, and software developers for fault‑current calculation tools. It is used for network planning, protection coordination, equipment rating verification and technical studies.

Q: Is it current or superseded?

A: IEC TR 60909-1:2002 remains the published Technical Report for Part 1 (publication date 31 July 2002) and is listed with a stability date in the IEC bibliographic record. It is a supporting TR to IEC 60909-0; users should verify the applicable editions of IEC 60909-0 and other parts for the latest mandatory calculation rules when performing new work.

Q: Is it part of a series?

A: Yes — it belongs to the IEC 60909 series on short-circuit currents (Part 0: calculation of currents; Part 1: this TR on factors; Part 2: equipment data; Part 3: special earth-fault cases; Part 4: worked examples). The TR is explicitly intended to be used together with IEC 60909-0.

Q: What are the key keywords?

A: Short-circuit, fault current, IEC 60909-0, correction factors, peak current, initial symmetrical current, X/R ratio, generators, transformers.