IEC 61869-2:2012

Overview

IEC 61869-2:2012 is an international standard establishing additional requirements specifically for inductive current transformers used with electrical measuring instruments and protective devices. It applies to new current transformers with rated frequencies between 15 Hz and 100 Hz. This standard supersedes earlier IEC standards IEC 60044-1 and IEC 60044-6, integrating technical innovations related to transient performance and modernizing requirements for current transformers. It is designed to be used alongside IEC 61869-1:2007, which covers general requirements for instrument transformers.

Published by the International Electrotechnical Commission (IEC), IEC 61869-2 ensures harmonization of quality, safety, and performance for current transformers used in electrical power systems worldwide. The standard covers ratings, design, test procedures, and performance criteria, supporting reliable measurement and protection in electrical networks.

Key Topics

• Scope and Applicability
  Focuses on inductive current transformers for frequencies from 15 Hz to 100 Hz, catering to both measuring and protective applications.

• Ratings
  Defines rated insulation levels, primary and secondary current ratings, thermal current ratings, and short-time withstand currents. It specifies accuracy classes for measuring (e.g., classes 0.1 to 1) and protective current transformers, including class assignments for selectable-ratio transformers.

• Design and Construction
  Covers design requirements such as temperature rise limits, inter-turn insulation, markings for terminals and rating plates, and core construction to ensure accuracy and durability.

• Testing Procedures
  Comprehensive testing includes temperature-rise tests, impulse voltage withstand tests, accuracy and short-time current tests, inter-turn overvoltage tests, and special tests like internal arc fault tests. Routine tests for production verification and sample tests for remanence factor and security factor assessments are also defined.

• Performance under Transient Conditions
  Introduces requirements for transient performance evaluation, ensuring transformers maintain accuracy and safety during dynamic network conditions such as fault currents.

Applications

IEC 61869-2:2012 is essential for manufacturers, testing laboratories, and utilities involved with current transformers in:

• Electrical power measurement systems
• Protection schemes in substations and grid infrastructure
• Design and certification of current transformers used in metering and relaying
• Ensuring compliance with international standards for safety, accuracy, and electromagnetic compatibility
• Assessment of current transformer performance during fault and transient events, critical for grid stability and protection coordination

This standard supports improved reliability in electrical power systems by providing a rigorous framework for the specification, design, and validation of current transformers.

Related Standards

• IEC 61869-1:2007 – General requirements for instrument transformers; to be read in conjunction with IEC 61869-2.
• IEC 60044-1 and IEC 60044-6 – Older standards on current transformers, now replaced by IEC 61869-2.
• IEC 61869 (overall series) – Covers all aspects of instrument transformers including voltage transformers and other related parts.

Keywords

Instrument transformers, current transformers, IEC 61869-2, inductive current transformers, electrical measuring instruments, electrical protective devices, rated frequency, accuracy classes, transient performance, temperature rise test, impulse voltage withstand test, electrical power measurement, protection schemes, substation equipment, current transformer testing, insulation level, thermal current rating, short-time current rating, IEC standards.