IEC 61869-10:2017

Overview

IEC 61869-10:2017 is an international standard developed by the International Electrotechnical Commission (IEC) focusing on instrument transformers, specifically addressing additional requirements for low-power passive current transformers (LPCTs). This standard forms part 10 of the IEC 61869 series and supplements the general and specific requirements outlined in IEC 61869-1 and IEC 61869-6.

Primarily applicable to newly manufactured LPCTs with analogue outputs, the standard covers transformers intended for use with electrical measuring instruments and protective devices, operating within a rated frequency range of 15 Hz to 100 Hz. It applies broadly to LPCTs used both for measurement and protection functions, including multi-purpose units.

This edition replaces the earlier IEC 60044-8 (2002) publication, reflecting a significant technical revision that aligns with the restructuring of IEC TC 38's standards series for instrument transformers.

Key Topics

• Scope and Application: The standard addresses only additional requirements, complementing the broader product family standards for LPCTs.

• Ratings and Performance Parameters: Defines standard values related to rated primary current, rated output, insulation levels, accuracy classes, and thermal current capabilities.

• Design and Construction Requirements: Emphasizes critical elements such as electromagnetic compatibility (EMC), marking conventions on terminals, signal-to-noise performance, reliability, vibrations resistance, and failure detection.

• Testing Procedures: Specifies type tests, general and special tests including accuracy assessments, thermal withstand tests, and positional accuracy tests.

• Accuracy and Ratio Correction: Details the designation of accuracy classes, considering corrected transformation ratios and ratio correction factors to enhance measurement precision.

• Optical and Electrical Output Systems: Outlines specific requirements for signal transmission systems, whether optical or electrical, to ensure consistent performance and maintenance transparency.

• Informative Annexes: Provide foundational knowledge on key technologies such as Rogowski coils and iron core LPCT operation principles, enhancing understanding of device functionality and accuracy features.

Applications

IEC 61869-10:2017 is tailored for applications including:

• Electrical Power Measurement: Ensuring accurate current measurement in power distribution and generation systems.

• Protective Relaying: Facilitating reliable current sensing needed for protective relays that safeguard electrical networks against faults.

• Multi-Purpose Current Transformers: Supporting devices that serve both metering and protection functions, optimizing installation and operational efficiency.

• Analog Signal Output Systems: Governing LPCTs with analogue outputs for compatibility with traditional electrical measuring instruments.

The emphasis on low-power and passive designs aligns with modern power system needs, providing improved safety, reduced energy consumption, and enhanced measurement accuracy.

Related Standards

• IEC 61869-1: General requirements for instrument transformers, establishing foundational principles governing performance, safety, and testing.

• IEC 61869-6: Specific requirements for low-power instrument transformers, serving as the key companion document to IEC 61869-10.

• IEC 61869-8 / IEC 61869-9: Additional parts of the IEC 61869 series that collectively replaced the earlier IEC 60044 series, standardizing instrument transformer requirements.

• IEC 60044-8 (superseded): The previous standard for low-power current transformers, now technically revised and integrated into the IEC 61869 series.

By following IEC 61869-10, manufacturers and users of low-power passive current transformers ensure compliance with internationally recognized benchmarks, enhancing interoperability and safety in electrical power systems.

Keywords: IEC 61869-10, low-power passive current transformers, instrument transformers, LPCT, electrical measurement, protective devices, analogue output, accuracy class, rated current, electromagnetic compatibility, IEC standards, current transformer testing, Rogowski coil, iron core transformer.