Angelo Campoccia

Financial measures for supporting wind power systems in Europe: A comparison between green tags and feed’in tariffs

Distributed Generation demonstrates to be able to significantly influence the electric power system, bringing considerable benefits to the quality of service and improving the energetic efficiency of the distribution network. In particular, in the last few years, Distributed Generation from renewable energy sources is considerably increased thanks to the many support policies promoted worldwide with the aim of facing the environmental issue and the problem of the permanent rise of prices of the fossil energy. In this contest, after a brief review on the financing strategies carried out in Europe in the last decade for promoting the recourse to renewable energy, the paper presents a comparison among the main support strategies for Wind Farms (Feed-in tariffs and Green Tags), taking into account the situation in some European Countries.

A Method to Evaluate Voltages to Earth During an Earth Fault in an HV Network in a System of Interconnected Earth Electrodes of MV/LV Substations

An easy and swift method to evaluate, in a system of interconnected earth electrodes, earth potentials on earthing systems of medium-voltage/low-voltage (MV/LV) substations, in an event of single-line-to-earth fault inside a high-voltage/medium- voltage (HV/MV) station, is presented. The advantage of the method is the simplicity of the mathematical model for solving complex systems of any size with a sufficient accuracy for practical purposes. This paper shows the results of simulations, performed on networks with different extensions and characteristics, organized in easy-to-read graphs and tables. A comparison of these results with the values obtained according to the procedure explained in the IEC-Standard 60909-3, and a study on the accuracy of the method has been made. Moreover, some considerations on the inclusion of earth electrodes of HV/MV stations within global earthing systems are done.

The Global Grounding System: Definitions and guidelines

The present paper presents the preliminary results of the ongoing Italian METERGLOB project on the contribution given by the exposed conductive parts to a Global Grounding System. One of the expected results of METERGLOB is to carry out guidelines for the identification of a Global Grounding System. These guidelines must be defined on the basis of the definitions and methods present in the current international standards on grounding and safety. In the paper some definitions and elements to be taken into account for the identification of a Global Grounding System are given.

Economic impact of Ice Thermal Energy Storage Systems in residential buildings in presence of double-tariffs contracts for electricity

The current paper presents a study on the effects of the installation of Ice Thermal Energy Storage Systems for cooling on the power daily profile of residential buildings, and examines the economic repercussions on the electricity billing. With reference to this second theme, the paper examines, in particular, the convenience of the installation of a domestic Thermal Energy Storage Systems, in presence of a doubletariff contract for electricity. For the estimation of the daily cooling request and power profile a Monte Carlo approach is used.

Analysis of interconnected earthing systems of MV/LV substations in urban areas

The paper proposes a study of the fault current distribution in an extended interconnection of earthing systems, belonging to secondary substations, during a single-line-to-earth fault. By applying the analysis methodology defined by the same authors in some previous works, the paper shows how the value of some important geometrical and electrical parameters of a MV network can influence the value of the earth current at the fault location.

A new methodology for distribution systems faults identification, location and characterization

Purpose – Identify a new methodology for fault characterization, identification and location in electrical distribution systems, based on the use of matrix algebra.Design/methodology/approach – The developed diagnostic methodology is based on a high precision analytical model of the network using a distributed parameters representation.Findings – Test results have proved the approach to be efficient and precise, while providing a generalized quadripolar model of a line affected by the most common kinds of fault.Research limitations/implications – Generalization to a greater number of fault cases, experimental tests.Practical implications – Utilities are quite interested in such items, since the new required quality standards put severe constraints on faults management and clearance. On the other hand, the system requires a rather complete measurement equipment of secondary substations.Originality/value – The paper presents a new diagnostic technique for faults identification, location and characterization...

Reliability analysis of a stand-alone PV system for the supply of a remote electric load

The work presents a reliability analysis of a stand-alone photovoltaic system for the supply of electric loads located in remote areas not easily reachable by the low voltage distribution network. The analysis is performed by characterizing the electric load behavior by means of a Montecarlo approach for taking into account the stochastic variability of the electrical energy demand. A Montecarlo approach is used also for evaluating the electricity production of the stand alone photovoltaic system as a function of the hourly solar irradiation of the installation site. The variability both of the load and of the energy production are correlated and the probability that the load can remain unsupplied for a certain time can thus be evaluated. Finally the reliability of the stand-alone system is compared with the reliability of an eventual connection to the grid as a function of the length of the connection line.

A generalized methodology for distribution systems faults identification, location and characterization

Service continuity is of basic importance in the definition of the quality of the electrical energy, for this reason, the research in the field of faults diagnostic for distribution systems is spreading ever more. In this paper, a new methodology for diagnostic management of automated distribution systems is presented. The technique is based on the solution of a circuital model of the electrical system resulting from the composition of distributed parameters quadripoles. The solution gives as a result the identification of the type of fault, of its characteristic parameters and location. The paper shows an application to line to line grounded and ungrounded faults in which also its precision and robustness to parametric variations are tested. The methodology can be extended to all the must common types of faults. Finally other runs show the comparison between the distributed parameters model.

A mathematical approach for studying interconnected earthing systems inside MV networks

Purpose – The purpose of this paper is to define a new methodology for studying interconnected earthing system inside unearthed medium voltage (MV) networks.Design/methodology/approach – The developed methodology is based on the division of the MV network into simpler sub‐systems and its resolution using a multiport approach.Findings – The methodology has been applied to various situations giving precious information on the behaviour of the interconnected earthing systems. The comparison between the results of the simulations and measurements done on a really existing network has shown that the methodology is able to provide accurate results.Research limitations/implications – Some factors can influence the precision of the methodology. Indeed, for a correct simulation of the system it is necessary to know several electrical and geometrical parameters, often obtainable with difficulty.Practical implications – Utilities are quite interested in this topic. The study of interconnected earthing systems in MV ...

An analysis methodology to evaluate the contribution to electrical security given by bare buried conductors in a system of intertied earthing grids

The paper presents an analysis methodology for a single-line-to-ground fault, occurring at a secondary MV/LV substation in a power network formed by a HV/MV station, feeding, through a MV tri-phase cable line, N MV/LV substations whose earth electrodes are interconnected by bare buried conductors. In the preliminary explanation of the methodology, earth buried conductors are studied in their double function of earth electrodes and connection elements between earthing grids, both in absence and in presence of other interfering conductors. Subsequently analyzed is, with a distributed parameters approach, the system constituted by an earth buried conductor and a MV tri-phase cable line. The equations that describe the system behaviour are solved with the decoupling method of modal analysis. The proposed methodology allows the determination of the currents injected in the ground by the buried conductor and by the earth electrodes of the substations, as a consequence of an earth fault, whichever is the faulty substation. A numerical example clarifies the presented methodology.