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Both Standards EN 50522 and IEEE 81 propose the fall of potential method (FPM) to carry out the measurement of the resistance to earth ($R_{\text{ES}}$) of an earthing system (ES). However, in urban areas, the recommended distances between the ES and auxiliary electrodes are not easy to respect, due to the presence of buildings and tarmac. Furthermore, unknown buried metallic parts and interconnections among ESs could modify the earth potential profile of the area, affecting the measurement results. In this paper, the key-issues that influence the measured $R_{\text{ES}}$ when the FPM is used in an urban environment are presented. A parametric analysis, carried out with Comsol Multiphysics, quantifies the errors due to wrong positioning of the auxiliary electrodes and due to the presence of interconnected ESs in the proximity of the ES under test. In addition, a real case of field measurement is described, emphasizing the main aspects that could compromise the results. Finally, practical suggestions to reduce errors are provided. [ABSTRACT FROM AUTHOR]

When a single line to ground fault (SLGF) happens on the MV side of an HV/MV system, only a small portion of the fault current is injected into the ground by the ground grid of the faulty substation. In fact, the fault current is distributed between grounding electrodes and MV cables sheaths. In systems with isolated neutral or with resonant earthing, this may be sufficient to provide safety from electric shock. Experimental measurements were performed on a real MV distribution network: a real SLGF was made and fault currents were measured in the faulty substation and in four neighboring substations. In this paper, the problem of fault current distribution is introduced, the test system is described and the measurements results are presented. [ABSTRACT FROM AUTHOR]

In this paper, an original scheduling approach for optimal dispatch of electrical Energy Storage Systems (ESS) in modern distribution networks is proposed. The control system is based on fuzzy rules and does not use forecasts since it repairs the past history according to the real time data on the electrical energy cost, renewable energy production and load. When the system detects a worsening of performances, the fuzzy logic rule-based control system self-adapts its membership functions using an economic indicator. The common use, in the relevant literature, of forecasted values in such systems can lead to large errors and economic losses. Moreover the speed of calculation guaranteed by the fuzzy control system allows the execution of new calculations even with high frequency. After the Introduction section, where the state of the art on the topic is outlined, the problem formulation is presented and an interesting application of the considered approach to the control on a medium size battery with real world data is proposed. [ABSTRACT FROM AUTHOR]