MEASURING RELAYS AND PROTECTION EQUIPMENT - PART 121: FUNCTIONAL REQUIREMENTS FOR DISTANCE PROTECTION
International Electrotechnical Committee
FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 Specification of the function
5 Performance specifications
6 Functional tests
7 Documentation requirements
Annex A (informative) - Impedance characteristics
Annex B (informative) - Informative guide for the behaviour
of timers in distance protection zones for
evolving faults
Annex C (normative) - Setting example
Annex D (normative) - Calculation of mean, median
and mode
Annex E (informative) - CT saturation and influence on
the performance of distance relays
Annex F (informative) - Informative guide for testing
distance relays based on CT requirements
specification
Annex G (informative) - Informative guide for dimensioning
of CTs for distance protection
Annex H (normative) - Calculation of relay settings based
on generic point P expressed in terms of voltage
and current
Annex I (normative) - Ramping methods for testing the basic
characteristic accuracy
Annex J (normative) - Definition of fault inception angle
Annex K (normative) - Capacitive voltage instrument
transformer model
Defines minimum requirements for functional and performance evaluation of distance protection function typically used in, but not limited to, line applications for effectively earthed, three-phase power systems.
| Document Type | Standard |
| Status | Current |
| Publisher | International Electrotechnical Committee |
| Committee | TC 95 |
| Supersedes |
|
