JWG 12 - TC 8/JWG 12

IEC TS 62786-42:2026 defines minimum requirements for AC voltage measurement used to control distributed energy resources (DER) and loads connected to distribution networks.
This document specifies the characteristics of voltage magnitude measurement to evaluate their performances (including voltage and frequency measuring range, accuracy, voltage and frequency operating range, resolution, etc).
This document describes the main use cases of voltage measurement, with associated level of performances.
This document 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 voltage measurement which can be embedded inside DER or loads controller or performed as an external control system. In the case of DER, this document is a subpart of requirements which are defined in the other parts of the IEC 62786 series.
This document is applicable to DER and loads regardless of voltage level at the point of connection to the distribution grid.
This document does not specify hardware, software or a method for voltage measurement. It does not specify tests linked to environmental conditions associated to hardware devices (climatic, mechanical stress, electromagnetic compatibility test, etc).

IEC TS 62786-41:2023 (E), which is a Technical Specification, defines minimum requirements for frequency and rate of change of frequency measurements used to control distributed energy resources (DER) and loads connected to electrical power networks.
This document specifies the characteristics of frequency and rate of change of frequency measurements to evaluate their performances. It describes the main use cases of frequency and rate of change of frequency measurements, with associated level of performances. 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 measurements which can be inside or outside the DER or loads. In the case of DER, this document provides requirements additional to those which are defined in the other parts of IEC 62786 or 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)).
This document is applicable to DER and loads regardless of the voltage level of the point of connection to the grid.
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 60255 118 1.
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.