IEC TR 61850-90-20:2025

IEC TR 61850-90-20:2025, which is a technical report, describes use cases of redundancy in systems.
This document considers use cases of duplication of function and devices and covers redundancy of information flow at message level. Functional safety is out of scope of this document. To keep focus on details relevant for this document, some figures and drawings do not show electrical wiring, redundant coils, etc, where this is not important for the use case.
This document is not a guideline on the design of redundancy systems; guidance on designing redundancy systems can be found in textbooks