PURPOSE AND SCOPE

This specification is a station function specification within the substation information, control and protection suite of technical specifications.

This Specification describes the functional and performance requirements for communication services used to convey teleprotection information. This includes communication requirements for unit protection, direct transfer trip systems, permissive under-reach, blocked over-reach and DAR control signalling.

The Specification primarily covers inter-substation communication and the interface presented to the relevant S/S applications but also defines some aspects of communication networks for teleprotection within a S/S.

The Specification defines the teleprotection requirements for the following types of channel:

• Digitally presented channels.

• Four wire, voice frequency presented channels (non power- line carrier) in exceptional cases for legacy applications.

The overall context of this specification in relation to the complete documentation suite is explained in TS 3.24.3. Additionally it should be noted that this specification is to be read in conjunction with TP133 and TGN138.