I.S. EN IEC 60255-187-1:2021
Current
The latest, up-to-date edition.
Measuring relays and protection equipment - Part 187-1: Functional requirements for differential protection - Restrained and unrestrained differential protection of motors, generators and transformers(IEC 60255-187-1:2021)
Hardcopy , PDF
English
04-10-2021
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FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 Specification of the function
5 Performance specification
6 Functional tests
7 Documentation requirements
Annex A (informative) Examples of phase (vector) compensation and zero sequence
compensation schemes
Annex B (normative) Calculation of mean, median and mode
Annex C (normative) CT requirements
Annex D (informative) CT saturation and influence on the performance of differential
relays
Annex E (informative) Guidance on dimensioning of CTs for transformer differential
protection
Annex F (informative) Examples of test procedures to determine CT sizing
requirements for differential protection
Annex G (normative) Ramping methods for testing basic characteristic accuracy
Annex H (informative) Example of COMTRADE file for an evolving fault test case
Annex I (normative) Definition of fault inception angle
Bibliography
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