Standards Development

Scope

This standard defines minimum requirements for frequency and rate of change of frequency measurement functions used to control electrical energy generators and loads connected to electrical power networks.

This document is applicable regardless of the voltage level of the point of connection to the grid and the power capacity of the installation.

This document specifies the characteristics of frequency and rate of change of frequency measurement functions to evaluate their performances. It describes the main use cases of frequency and rate of change of frequency measurements, with associated levels of performance. It describes the principle of functional tests to evaluate the specified characteristics and defines the influencing factors that affect these performances, under steady state or dynamic conditions.

This document defines the functional requirements applicable to frequency and rate of change of frequency measurement functions which can be managed within the equipment (generator or load) or using and external device. In the case of generators, this document provides requirements additional to those which are defined in the other standards produced by the relevant IEC technical committees (e.g. TC 82 for photovoltaic systems, TC 88 for wind systems, TC 120 for electrical energy storage systems (EES), TC22 and its subcommittees (SC22E, SC22F) for inverter-based generators. IEC mapping of these standards is recalled in Annex XX (TC8/JWG12 comment: This Annex will be proposed in the next CD, with inputs from IEC TR 62786-100)

This document does not specify hardware, software or a method for frequency or rate of change of frequency measurement. It does not specify tests linked to environmental conditions associated with hardware devices (climatic, electromagnetic disturbances above 3 kHz, mechanical stress, etc.).

Frequency and rate of change of frequency measurements associated with time stamping are not in the scope of this document. These measurements are already covered by IEC/IEEE 60255-118-1 [2].

Frequency and rate of change of frequency measurements associated with protection functions or protection relays are not in the scope of this document. These requirements are already covered by IEC 60255-181 [3].

This document is mainly focused on control functions of generators and loads but it can be also used for other devices or systems which are using fast frequency or rate of change of frequency measurement functions as, for example, power meter devices, power quality instruments, Energy Management Systems (EMS), Power Management Systems (PMS).