This paper introduces an algorithm able to detect and localize the occurrence of a fault in an Active Distribution Network, using the measurements collected by Phasor Measurement Units (PMUs). First, a basic algorithm that works under the assumption that all grid buses are equipped with a PMU is designed. Then, formal observability conditions that allow detection and localization with a reduced number of PMUs are provided. Based on these conditions, the algorithm is extended to perform correctly when not all network buses are monitored. Moreover, an Optimal Positioning Algorithm, always based on the observability conditions, is designed. This algorithm allows the user to customize the fault localization resolution. The approach is validated through simulations carried out on a benchmark active distribution network.

This paper considers the problem of fault detection and localization in active distribution networks using Phasor Measurement Units (PMUs). The proposed algorithm consists in computing a set of weighted least squares state estimates whose results are used to detect, characterize and localize the occurrence of a fault. Moreover, a criteria to minimize the number of PMUs required to correctly perform the proposed algorithm is defined. Such a criteria, based on system observability conditions, allows the design of an optimization problem to set the positions of PMUs along the grid, in order to get the desired fault localization resolution. The performances of the strategy are tested via simulations on a benchmark distribution system.

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In this paper, a method to evaluate the flexibility of aggregates of domestic electric water heaters is proposed and applied to the Italian case. Flexibility is defined as the capability of the aggregate to vary its power demand for a given time interval. The evaluation method consists of a Monte Carlo analysis, that uses the thermal model of electric water heaters and a proper elaboration of the external inputs, such as ambient and cold water temperatures, and hot water demand. The case of large aggregates defined along the Italian territory has been studied showing the dependence of flexibility on seasons and on time.