GB/T 15544.1-2013
Short-circuit current calculation in three-phase a.c.systems.Part 1:Calculation of currents (English Version)

Standard No.

GB/T 15544.1-2013

Language

Chinese, Available in English version

Release Date

2013

Published By

General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China

Status

Be replaced 2023-10

Replace By

GB/T 15544.1-2023

Latest

GB/T 15544.1-2023

Replace

GB/T 15544-1995

Scope

This part of GB/T 15544 applies to the calculation of short-circuit current in low-voltage and high-voltage three-phase AC systems with a rated frequency of 50 Hz or 60 Hz. Special consideration is required when the nominal voltage of the system is 500 kV and above and contains long-distance AC transmission lines. The short-circuit point equivalent voltage source method proposed in this section is a simple and practical short-circuit current calculation method, and its calculation results generally have acceptable accuracy. If the same calculation accuracy can be obtained, other calculation methods, such as the superposition method, are not excluded. The short-circuit current calculated by the superposition method depends on a specific power flow, so it is not necessarily the maximum short-circuit current. The short-circuit forms involved in this section include balanced short-circuit faults and unbalanced short-circuit faults. For an artificial or accidental short circuit between a line conductor and the earth, the physical characteristics and effects of the following two cases are different (resulting in different calculation purposes), and must be clearly distinguished: In the system, the conductor is short-circuited to ground; -- In the neutral point ungrounded or resonantly grounded system, a conductor-to-ground short-circuit fault occurs, and the calculation of the short-circuit fault is not within the scope of this part of the study. In the neutral point ungrounded or resonant grounded system, when two independent single-phase ground short-circuit faults occur simultaneously, the calculation of the short-circuit current refers to IEC 60909-3. Short-circuit current and short-circuit impedance can also be determined through system test, system analysis instrument measurement or digital computer. In the existing low-voltage system, the short-circuit impedance can be obtained by measuring the expected short-circuit point. The calculation of short-circuit impedance is usually based on the rated parameters of the power equipment and the topology of the system. The advantage of this method is that it can be applied to both the existing system and the planned system. Normally, two short-circuit currents with different amplitudes should be calculated: -- the maximum short-circuit current, used to select the capacity or rated value of electrical equipment; -- the minimum short-circuit current, used to select fuses, set protection settings or Check induction motor start. This section does not apply to man-made short-circuits and short-circuit calculations for electrical equipment used in aircraft and ships under controlled conditions (short-circuit test station).

GB/T 15544.1-2013 Referenced Document

• IEC 60038:2002 IEC standard voltages
• IEC 60050-131:1978 International Electrotechnical Vocabulary. Part 131 : Electric and magnetic circuits
• IEC 60050-151:1978 International Electrotechnical Vocabulary. Part 151 : Electrical and magnetic devices
• IEC 60050-195:1998 International Electrotechnical Vocabulary - Part 195: Earthing and protection against electric shock
• IEC 60056:1987 High-voltage alternating-current circuit-breakers
• IEC 60071-1:1993 Insulation co-ordination - Part 1: Definitions, principles and rules
• IEC 60781:1989 Application guide for calculation of short-circuit currents in low-voltage radial systems
• IEC 60865-1:1993 Short-circuit currents; calculation of effects; part 1: definitions and calculation methods
• IEC 60909-3:1995 Short-circuit current calculation in three-phase a.c. systems - Part 3: Currents during two separate simultaneous single phase line-to-earth short circuits and partial short-circuit currents flowing through earth
• IEC 60949:1988 Calculation of thermally permissible short-circuit currents, taking into account non-adiabatic heating effects
• IEC 60986:1989 Guide to the short-circuit temperature limits of electric cables with a rated voltage from 1,8/3 (3,6) kV to 18/30 (36) kV

GB/T 15544.1-2013 history

• 2023 GB/T 15544.1-2023 Short-circuit current calculations for three-phase AC systems Part 1: Current calculations
• 2013 GB/T 15544.1-2013 Short-circuit current calculation in three-phase a.c.systems.Part 1:Calculation of currents
• 1995 GB/T 15544-1995 Short-circuit current calculation in three-phase a.c.systems

GB/T 15544.1-2013 -All Parts