IEC 61869-11:2017

Overview

IEC 61869-11:2017 is an international standard published by the International Electrotechnical Commission (IEC) that specifies additional requirements for low-power passive voltage transformers (LPVTs). This standard is a part of the IEC 61869 series on instrument transformers and focuses specifically on passive LPVTs with analogue output for rated frequencies ranging from 15 Hz to 100 Hz. These transformers are predominantly used for electrical measurement and protection purposes.

Low-power passive voltage transformers covered by IEC 61869-11 provide a secondary voltage proportional to the primary voltage; however, derivative outputs or active electronic components are outside this scope. This edition supersedes and replaces relevant clauses from the earlier IEC 60044-7 (1999) and IEC 60044-8 (2002), representing an important technical revision.

Key Topics

• Scope and Application
  Covers only passive LPVTs with analogue outputs, including those with an integrated secondary signal cable. Excludes active or digital outputs (addressed in future IEC 61869-7). Applicable for new transformers designed for measurement, protection, or both.

• Design and Construction Requirements
  Sets forth mandatory design features including electromagnetic compatibility (EMC), insulation levels, voltage ratings, and marking requirements. It also details provisions for optical and electrical transmitting systems, failure detection, reliability, transient response, and voltage limitation devices.

• Rated Characteristics and Accuracy
  Defines rating parameters such as insulation levels, rated output, frequency range (15 Hz to 100 Hz), and accuracy classes. It also provides standard values for rated voltages and voltage factors essential to product specification and testing.

• Testing Protocols
  Specifies general, routine, type, and special tests to ensure performance, safety, and reliability. Tests include dielectric withstand, accuracy verification, transient response, and impact from external electric fields.

• Documentation and Labelling
  Outlines requirements for clear designation, markings on transformers, and information to be supplied with inquiries and orders to facilitate correct identification and usage.

Applications

IEC 61869-11 low-power passive voltage transformers are critical in modern electrical systems for accurate voltage measurement and protection:

• Electrical Measuring Instruments
  Provide precise voltage scaling for measurement devices in substations, generation plants, and electrical distribution networks.

• Protection Relays and Systems
  Feed voltage signals into protective relays to detect abnormal operating conditions and trigger protective actions.

• Multipurpose Usage
  Designed to serve both measurement and protection functions, increasing versatility and reducing the need for separate transformers.

• Integration with Analog Instrumentation
  Ideal for deployments reliant on analogue voltage signals in control and monitoring systems.

These LPVTs contribute to enhanced system safety, accuracy, and efficiency in power generation, transmission, and distribution industries.

Related Standards

• IEC 61869-1: General Requirements
  Provides the fundamental general requirements for instrument transformers, serving as the baseline for this part.

• IEC 61869-6: Additional Requirements for Low-Power Instrument Transformers
  Supplements IEC 61869-1 with added requirements relevant to low-power transformers, forming the structural basis for Part 11.

• IEC 61869-7: Requirements for Low-Power Active Instrument Transformers (forthcoming)
  Addresses active electronic technologies and digital output devices not covered by Part 11.

• Predecessor Standards: IEC 60044-7 and IEC 60044-8
  Older standards replaced by the IEC 61869 series, previously governing LPVTs and related transformers.

Practical Value

Adherence to IEC 61869-11 ensures that low-power passive voltage transformers:

• Meet internationally recognized safety and performance benchmarks
• Deliver consistent and reliable analogue voltage outputs
• Provide documented accuracy and reliability to support power system protection and measurement
• Are tested rigorously under defined conditions for assured durability
• Include clear labeling and specifications for simplified procurement and application

This standard is essential for manufacturers, engineers, and procurement professionals involved in the specification, design, and deployment of LPVTs in electrical power systems worldwide.

Keywords: IEC 61869-11, low-power passive voltage transformer, LPVT, instrument transformers, electrical measurement, protection relays, analogue output transformer, voltage transformer standard, IEC instrument transformer standards, electrical safety, power system measurement, transformer accuracy.