standard byInternational Electrotechnical Commission , 08/01/2025
IEC 60255-216-1:2025 covers protection functions with digital inputs and outputs complying with
IEC 61850 series and IEC 61869 series, in particular regarding
– subscription to sampled values (SV) streams representing energising inputs instead of
analog inputs (see Figure 1);
– subscription to GOOSE (e.g. circuit breaker position, circuit breaker failure);
– publication of GOOSE messages (e.g. trip signals);
– subscription to time synchronisation messages.
On this basis, this document formulates requirements for protection functions with digital inputs
and outputs and for the IED hosting them. The document also covers tests related to the
functional interoperability and functional requirements of these protection functions, in addition
to the general conformance tests required by IEC 61850-10:2012 and test related requirements
in IEC TR 61850-10-3:2022 [1]1.
Requirements regarding characteristics of the communication network are not within the scope
of this document. Delays and jitter due to the network are taken into account by network
engineering. The expected behaviour of protection functions in case of delays, jitter or loss of
SV is covered by this document. Figure 1 below shows the functional chain of a protection
function, where each IED is connected to the PACS communication network. This document
only considers the data received and published by the protection function as shown in Figure 1.
It describes the coordination between the digitally interfaced protection functions and the
characteristics of the analog acquisition chain.
If not mentioned otherwise, the term “switch” in this document refers to the switches used in
the communication network.
The PACS communication network engineering and cyber security measures to be applied on
PACS level are out of scope of this document.
Requirements for protection functions switching over between two redundant SV streams
acquired by different acquisition chains but reflecting the same primary values are covered in
this document.
This document is applicable to protection functions for AC networks implemented in IEDs
subscribing SV streams. Parts of the considerations can also apply to IEDs combining analog
inputs connected to Instrument Transformers and SV subscription.
If an IED hosting protection functions is interfacing analog inputs connected to Instrument
Transformers and publishes the associated SV streams, it is a multifunctional IED and complies
additionally with the relevant IEC 61869 standards. This type of device is out of scope of this
document.
Some aspects related to cyber security are considered in this document, e.g. reception of
duplicated or corrupted messages. The implementation of specific cyber security standards,
such as IEC 62351-6 [2] is covered by the general implementation requirements of the
IEC 61850 series. Detailed cyber security requirements for IEDs hosting protection functions
are out of scope of this document.
