Revision of target uncertainty for PMU-based distributed measurement systems in MV networks

Abstract

The need for accurate measurements is daily increasing and recognized by system operators. Whether this aspect may be less significant for transmission networks (TNs), the same is not true for the distribution one (DN). In fact, the investments dedicated to TNs are far higher compared to those for DNs. Therefore, this work deals with the accuracy requirements needed in DNs to achieve significant measurement results. In particular, the study starts from the hypothesis that measurements are collected from typical current and voltage sensors and computed via phasor measurement units. The work first describes the typical characteristics of the DN. Second, the sources of uncertainty that contribute to the overall uncertainty of the output quantities (module and phase of currents and voltages) are detailed and analyzed. Finally, the Monte Carlo method has been applied to quantify the uncertainty of those quantities in a variety of realistic DN configurations. From the results, it emerges the significance of the measurement chain design due to its significant impact on the accuracy of the measured quantities.