The expected evolution of distribution networks will bring various benefits such as increased efficiency, reduced pollutant emissions, and high continuity and quality of service, but at the same time, it will raise multiple challenges related to the observability of the network.

Distribution networks are characterized by limited measurements provided by metering devices installed at critical points in the network. However, these measurements are not synchronized and have a low update frequency, causing errors in the estimation of the network state. For this reason, in recent times, synchrophasor measurement systems designed for distribution networks have been developed, which can be installed in the distribution network to improve its observability by integrating these measurements with those already available.

Given these premises, the first part of the activity described below focused on analyzing the state of the art concerning topics related to network state estimation, network impedance estimation, islanding detection, and topological reconstruction. These latter three topics are of fundamental importance in network state estimation, which generally uses information such as the admittance matrix to reconstruct all quantities that are not directly measured. Errors in creating the admittance matrix, caused by incorrect knowledge of network information, must be avoided by reconstructing missing information as well. Furthermore, given the high cost of Phasor Measurment Units (PMUs), methods must be identified to perform optimal placement of the PMUs, reducing the cost of the measurement infrastructure while ensuring network observability. From the analysis of the state of the art, it is clear that an optimal solution that can be applied to distribution networks and that allows for the integration of PMU and traditional measurements has not yet been identified.

In the second part of the activity, a low-voltage distribution network model was also defined, which takes into account the presence of renewable energy generation, storage systems, direct current portions and connections, and the loop operation of the network in alternating current. This model can be used to validate state estimation algorithms. The benchmark network defined based on the IEEE European Low Voltage Test Feeder thus considers future developments in the distribution network. The developed phasor-type model has been incorporated with experimental data from the RSE Test Facility and will allow verification of the algorithms to be developed in upcoming research activities in a simulation environment..