Calibration of Synchronized Measurement System: from the Instrument Transformer to the PMU

Even if their deployment in electrical medium voltage networks was not as extensive as could be expected at the beginning, Phasor Measurement Units are key elements for Smart Grid operation. An impressive amount of papers discusses their implementation and usefulness in medium voltage network and almost as many deals with their metrological characterization. Although it is well known that instrument transformers are the main source of uncertainty in PMU-based synchronized measurements, this topic is not sufficiently tackled in the scientific literature. In this paper, the attention is focused on the calibration of a measurement system made by a PMU and a low-power instrument transformer commonly employed in the Italian distribution network.