This part of IEC 60255 specifies the minimum requirements for functional and performance 
evaluation of frequency protection. This document also defines how to document and publish 
performance test results. 
This document covers the functions based on frequency measurement or rate of change of 
frequency measurements. This document also covers frequency protection where additional 
blocking elements are used.  
This document defines the influencing factors that affect the accuracy under steady state 
conditions and performance characteristics during dynamic conditions. The test 
methodologies for verifying performance characteristics and accuracy are also included in this 
document.dition 1.0 2019-02 INTERNATIONAL STANDARD NORME INTERNATIONALE colour inside Measuring relays and protection equipment – Part 181: Functional requirements for frequency protection Relais de mesure et dispositifs de protection – Partie 181: Exigences fonctionnelles relatives aux protections de fréquence IEC 60255-181:2019-02(en-fr) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright ？ 2019 IEC, Gene