| abstract |
An intelligent electronic device (IED) integrating a power metering unit (PMU) and a merging unit that combines signals from both analog transformers and digital transformers into a set of merged digital samples. Analog current/voltage signals from analog CTs/PTs are received at the IED's analog inputs and converted to digitized samples. Digital current/voltage samples from digital CTs/PTs are received via point-to-point connections at digital inputs of the IED. A tagging unit applies metadata tags to the digitized and digital samples. The metadata tags include the transformer providing the input signal, sampling rate, primary and/or secondary timestamps, scaling values, calibration values, and/or the location of the IED in the electrical system. The PMU performs metering and/or power quality calculations on the samples, and the calculation results are formatted and transmitted via a master-slave protocol to a requesting master. A grouping unit groups the merged samples into default or custom groupings, which are formatted and transmitted over a network via a publish-subscribe mechanism. |