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Modern distribution networks prove to be easily prone to power quality issues, and in particular to the presence of harmonic. components in the voltage and current signals, due to the increasing presence of nonlinear loads, distributed generation, and renewable energy sources. In addition, the non-stationary operating conditions make the problem of harmonic phasors' estimation particularly challenging. The application of Phasor Measurement Units (PMUs) might represent a promising alternative to traditional approaches based on the Discrete Fourier Transform. In this paper, we propose to exploit two estimation techniques derived from recent PMU-based applications and discuss their estimation results in a real-world measurement. dataset, acquired in the medium voltage distribution network of EPFL campus.

This paper deals with the problem of convening the specifications of devices used in measurement systems based on digital signal processing into data that can be represented as probability density functions of the input quantities (samples) in a Monte Carlo procedure for uncertainty estimation. The attention is focused on data acquisition systems and input transducers. Author's proposals for facing this problem are based on the idea of considering separately the different uncertainty contributions, by defining for each of them appropriate pdf's and taking into account the correlation of their effects on the acquired samples to be processed. The advantages and limits of this approach are discussed with the help of experimental tests

This chapter deals with the study of the voltage and current sensors, that is, the devices used to convert the primary electrical quantities in the power grid into signals that can be properly managed by the input circuits of the Phasor Measurement Unit (PMU). In particular, it is discussed how the use of sensor technologies different from the classical magnetic core instrument transformers (eg, those based on voltage dividers and Rogowski coils) may enable performance much more suited to the metrological behavior required for PMUs in the different practical operating conditions.

Voltage transients are the main causes of complaints for medium-voltage customers, and hence interest is focused on investigation techniques able to help in classifying and localizing such events in accordance with their origin. In this light of fact, a distributed measurement system for performing synchronized acquisition of fast voltage transients is presented in this paper. The system, designed to fulfill specific constraints about the reliability of the provided information, has been used in a one-year long measurement campaign performed in a medium voltage network. The main obtained results are presented.