IEC 60255-121:2014
Current
The latest, up-to-date edition.
Measuring relays and protection equipment - Part 121: Functional requirements for distance protection
Hardcopy , PDF , PDF 3 Users , PDF 5 Users , PDF 9 Users
English - French
07-03-2014
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
IEC 60255-121:2014 specifies 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. This standard also defines how to document and publish performance tests. This standard covers distance protection function whose operating characteristic can be defined on an impedance plane and includes specification of the protection function, measurement characteristics, phase selection, directionality, starting and time delay characteristics. The test methodologies for verifying performance characteristics and accuracy are included in this standard. The standard defines the influencing factors that affect the accuracy under steady state conditions and performance characteristics during dynamic conditions. It also includes the instrument transformer requirements for the protection function. The general requirements for measuring relays and protection equipment are defined in IEC 60255-1.
DevelopmentNote |
Supersedes IEC 60255-16. (03/2014) Stability date: 2018. (09/2017)
|
DocumentType |
Standard
|
Pages |
302
|
PublisherName |
International Electrotechnical Committee
|
Status |
Current
|
Supersedes |
Standards | Relationship |
NF EN 60255-121 : 2014 | Identical |
NBN EN 60255-121 : 2014 | Identical |
NEN EN IEC 60255-121 : 2014 | Identical |
PN EN 60255-121 : 2014 | Identical |
VDE 0435-3121 : 2015 | Identical |
BS EN 60255-121:2014 | Identical |
CEI EN 60255-121 : 2014 | Identical |
EN 60255-121:2014 | Identical |
SAC GB/T 14598.121 : 2017 | Identical |
UNE-EN 60255-121:2014 | Identical |
PNE-FprEN 60255-121 | Identical |
PD IEC/TR 61869-100:2017 | Instrument transformers Guidance for application of current transformers in power system protection |
IEC TR 61869-100:2017 | Instrument transformers - Part 100: Guidance for application of current transformers in power system protection |
CEI EN IEC 61936-1:2024 | Power installations exceeding 1 kV AC and 1,5 kV DC Part 1: AC |
IEC 61869-2:2012 | Instrument transformers - Part 2: Additional requirements for current transformers |
IEC 60255-1:1967 | Electrical relays - Part 1: Instantaneous all-or-nothing relays |
IEC 61869-5:2011 | Instrument transformers - Part 5: Additional requirements for capacitor voltage transformers |
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