A draft reference architecture for a ROCOF instrument has been published here.

This reference implementation is intended as an aid to a manufacturer of a ROCOF instrument and is proposed as an informative to a ROCOF standard to demonstrate a method to implement a compliant instrument. This is a discussion document and we would welcome comments, suggestions and amendments. Please use the project web site comment box.

The architecture is intended to be as simple as possible for ROCOF and where appropriate, builds-on the existing IEEE C37.118.1 Annex C heterodyne based example, such that existing hardware can be used to implement ROCOF. The proposed reference model for a ROCOF instrument is divided into a sampling part (in hardware) and a processing part (in a processor, implemented by firmware and/or software).

If desired, other experts can extend the reference model to cover implementations of PMUs and/or Power Quality instruments. Other instrument architectures such as those based on phase locked loops and frequency estimators are not considered here.