What is BS EN IEC 61869‑14 - Current transformers for DC applications about?
BS EN IEC 61869‑14 is a safety standard on current transformers for DC applications.
BS EN IEC 61869‑14 provides all requirements specific to current transformers to be used in DC applications (DCCTs), whatever the technology used. The output signal can be analogue or digital.
BS EN IEC 61869‑14 is applicable to newly manufactured current transformers used for measuring, protection, and/or control applications in DC power systems with a rated voltage above 1,5 kV. BS EN IEC 61869‑14 describes the general configuration of a single-pole low-power instrument transformer.
Who is BS EN IEC 61869‑14 - Current transformers for DC applications for?
BS EN IEC 61869‑14 on requirements for current transformers for DC applications is relevant to:
- Electrical engineers
- Electromagnetic engineers
- Electricians and other officials of the electrical department
- Testing authorities
- Manufacturers of transducers and current transformers
Why should you use BS EN IEC 61869‑14 - Current transformers for DC applications?
Current transformers are the current-sensing units of the power system and are used at generating stations, electrical substations, and in industrial and commercial electric power distribution.
BS EN IEC 61869‑14 applies to current transformers intended to be used in DC applications with at least one of the following functions:
- Measure DC current (with significant harmonics)
- Withstand DC voltage
Depending on the position of the current transformer on the DC system, different kinds of applications exist, which are briefly described, together with the approximate voltage or current wave shape. BS EN IEC 61869‑14 assists the user with Line-commutated converters (LCC) and Voltage-source converters (VSC). Line-commutated converters (LCC) are based on thyristor converters. They are characterized by a single direction of current flow, and a voltage polarity reversal possibility. Significant voltage and current harmonics exist up to frequencies of about 3 kHz to 4 kHz. Voltage-source converters (VSC) are based on transistor converters. They are characterized by a bi-directional current flow and a single voltage polarity. Voltage and current harmonics exist up to frequencies of about 20 kHz. Two variants of VSC schemes exist, which are, symmetrical monopoles (using one single converter) and asymmetrical monopole or bipole (with one converter for each polarity). BS EN IEC 61869‑14 also assists with the test determines the average temperature rise of the primary conductor, the secondary windings (if present), the primary and secondary converters, and, for oil-immersed transformers, the temperature rise of the top oil, in steady-state conditions when the losses resulting from the specified service conditions are generated in the current transformer.
Overall, BS EN IEC 61869‑14 is useful as it provides guidance on the purpose of the test, which helps in measuring the accuracy on the DC component and on harmonic components when supplied simultaneously.
