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Electric vehicles (EVs) and the recent pandemic outbreak give cities a new trend to primarily private and shared mobility with low noise and less air pollution. Crucial factors for the widespread of EVs are the electrical charging infrastructure, driving range, and the reduction of the cost of battery packets. For this reason, there is a massive effort from manufacturers, governments, and the scientific community to reduce battery costs and boost sustainable electrical production and distribution. Battery reuse is an alternative to reduce batteries’ costs and environmental impacts. Second-life batteries can be used in a wide variety of secondary applications. Second-life batteries can be connected with off-grid or on-grid photovoltaic and wind systems, vehicle charging stations, forklifts, and frequency control. The present work aims to analyze the main challenges imposed on the reuse of batteries, the leading technologies for their reuse, and the different types of batteries in terms of their feasibility for second-life use. The main novelty of this work is the discussion about the barriers, opportunities, uncertainties, and technologies for the second life market. Here we summarize the present state of the art in reusing lithium-ion batteries discussing technical and economic feasibility, environmental impacts, and perspectives. The results show five business models that have been proposed in the literature, three types of markets for trading second-life batteries, and the main opportunities and barriers for each actor in the battery supply chain.

The Blorin project started at the end of 2019 to support the implementation of a blockchain platform to support the energy services provision from end users by means of Demand Response and Vehicle to Grid programs. The experimental part of the project is being carried out on two Mediterranean islands and inside the University campus in Palermo. Customized smart contracts have been designed to support the active participation of end users to regulation services for the two weak electrical grids of the islands in the view of a deep penetration of renewable energy in the two energy systems. In particular, the smart contract for remuneration accounts for the very special energy situation of islands where TSO, DSO, energy seller and aggregator collapse in a unique market actor. Moreover, in islands the electricity provision is typically still relying on diesel generators thus strongly connecting the Demand Response programs benefit to the reduction of fuel consumption, as an effect of increased efficiency of diesel generators. Due to the critical international situation and to the climate crisis, fossil fuels get more and more costly, thus a speed up of the energy transition in small islands is highly needed. This paper addresses the problem of designing a customized smart contract for remuneration of Demand Response service provision in small islands.

Transportation is one of the key sectors causing greenhouse gas (GHG) emissions and air pollution. With the substantial increase in passenger and freight transportation, the corresponding GHG emissions and air pollutants are expected to increase significantly. Recent global and national policies are targeting at reducing environmental impacts of transportation activities. The promotion of public transportation and development of electric buses (e-buses) will reduce the use of fossil fuels in transportation, and consequently, reduce GHG emissions. This study assesses the life cycle GHG emissions and other environmental impacts of e-bus, and compares them with those of conventional bus operated in Vietnam. The results indicate that e-bus is a preferred choice in most of studied environmental impact categories over the whole life cycle such as GHG emission, ozone depletion, ozone formation, fine particulate matter formation, acidification, etc. For GHG emissions, the adoption of electric mobility will reduce 42.62 gCO(2)eq per passenger km of carbon footprint if conventional buses are substituted by e-buses in Vietnam.

This chapter presents the outcomes of the experimental implementation of the architecture described in Chap. 4 running a hardware testbed for the emulation of domestic electrical load profiles. Besides it shows how this experimental scenario integrates both with the legacy metering architecture and with the blockchain platform. Finally, the integrated use with an Energy Management System designed on purpose is also described with the aim of ensuring intervention and automating the end user’s response to a DR event.

Sicily is one of the first Italian regions for installed power from renewable energy plants, especially photovoltaic and wind plants, and a crucial point for the Mediterranean energy hub. Its role as nexus between the European and the African Continents is becoming more and more significant due to the realization in a short time of the so called Tyrrhenian link and the High Voltage Direct Current (HVDC) connection with Tunisia. In this framework, the paper presents a model of the Sicily power generation and transmission system, including the Tyrrhenian link and two equivalent buses representing the Sardinian power network and the rest of the Continental Europe (CE) synchronous area, for both steady-state and dynamic analysis. The model is developed in Neplan and it is based on the actual structure of the Sicilian power system. The rest of the CE system is represented in the model and validated by a comparison with the large-scale dynamic model of the CE provided by the European Network of Transmission System Operators for Electricity (ENTSO-E). Finally, some simulations of the Sicilian grid in future energy scenarios are presented, and the behaviour of the system is discussed considering different transient conditions.

In this paper a model of PQ sources useful for distribution systems analysis is developed. In the considered systems there are, in addition to HV/MV sources, other PQ buses, namely active and reactive power supply nodes (Vδ nodes). The general solution strategy is an iterative forward/backward method, in which the state variables are the node voltages. If it is weakly meshed, the network is turned into radial by means of cuts and compensation currents. After the presentation of the general problem, the equations expressing the unknowns for the PQ nodes are treated in detail. These equations belong to the backward sweep of the algorithm. The methodology has been implemented and applied so as to test its performance in terms of calculation times and precision.

The present paper deals with the dependence of the ground current, due to a single-line-to-ground fault in a secondary substation, on the electrical and geometrical parameters of a Medium Voltage distribution network in which a metallic interconnection between the grounding systems is realized. Examining different situations, some easy-to-use tables are provided for a practical approach to the design of the ground electrodes of the secondary substations in these networks. The relevance of the work is due to the lack in the international standards of specific indications on how to consider the presence of the interconnection elements in distribution networks.

Cortical projections from the visual region and adjacent polysensory region of the superior temporal sulcus (STs) to the lateral geniculate body (LGb) were investigated in the macaque monkey using an autoradiographic tracing method. Solutions of tritiated aminoacids were injected into different parts of the caudal half of the STs of five animals. A survival time of 7 days was allowed. Labels were found in both subdivisions of the LGb: the dorsal lateral geniculate nucleus (DLGn) and the pregeniculate nucleus (PGn). In particular, part of the visual cortical region adjacent to the middle temporal area (MT) projects into the DLGn as well as the PGn, whereas the MT itself and the superior temporal polysensory region project into the PGn only. Afferents to the DLGn terminate in the magnocellular layers and in their adjoining interlaminar zones, completely sparing the parvocellular layers. Afferents to the PGn terminate in separate regions of this nucleus; the MT and adjacent visual cortices project into the internal layer of the PGn, whereas the polysensosy region of the STs projects into the external retinorecipient layer of the PGn. Possible functional implications of these projections are discussed.

A high level of power quality in distribution networks is obtained by means of a diagnostic software, that establishes on-line the status of the network, by elaborating the measured data. An efficient telecommunication system is necessary, from whose reliability depends the security of the timely interventions on the network in case of fault. In the paper, after a brief examination of the diagnostic method, the telecommunication system is examined. The WiFi system has been considered most suitable, for its economy, for the diagnostic service, besides it is not suitably reliable for how it is managed by the IEEE 802.11 protocol for this application. In this work a new protocol derived by the existing IEEE 802.11 is described, highlighting the improvements that it introduces and verifying its capability for the diagnostic service. An application shows its potentiality

Single unitresponses to photic stimuli of variable duration were studied in the cat visual areas 17 and 18. The closed-chamber technique was used to record extracellularly impulsive electrical activity in locally anaesthetized, Flaxedil-paralyzed and artificially ventilated cats. Stimulus duration ranges between 0.020 and 10 sec, the background luminance and the intensity of stimuli being constant. We found a first group of cells which fire independently of the stimulus duration; a second group which fire in close relation to the stimulus duration in a rather wide range of values, and a third group which fire monotonously as long as the stimulus goes on. The three groups of cells are supposed to be three functionally different types of cortical cells.

Issues related to the stability of non-interconnected grids are of high relevance given the increasing presence of renewable sources in the power generation system. In order to ensure adequate levels of system's reliability, it is necessary to find new methods to ensure the stability of the electric grid. The present work proposes a methodology for the definition of the minimum number of Vehicle-to-Grid (V2G) charging points that would allow the integration of 1 MW of photovoltaic power in the power grid of the Italian island of Favignana, electrically disconnected from the continental grid. Primary frequency regulation simulations are carried out in Matlab/Simulink environment for different scenarios related to the generation park. The results show that with a limited number of V2G points levels of stability of the electrical system comparable to those before the installation of the photovoltaic plants can be ensured.

This paper describes a blockchain-based approach for sharing data among all the actors involved in Vehicle-to-Grid programs. The shared information is used both for monitoring the health status of the vehicle’s battery and for remuneration in Vehicle-to-Grid programs. A blockchain platform and a set of appropriate smart contracts have been developed for supporting the interactions among the different actors and for creating battery usage profiles. To protect sensitive data, we limit the visibility scope of such data only to subsets of actors using blockchain channels. This approach preserves the privacy of the car owner on one hand and guarantees the compliance to correct charging and discharging modes, on the other hand, by using dedicated smart contracts to manage data for each of the channels. The approach here described proposes and develops a blockchain-based ecosystem for efficiently managing electric vehicles especially when these are called to provide electrical grid services, such as it happens for Vehicle-to-Grid programs. In this case, it is indeed possible that the battery undergoes an accelerated aging and thus certified recording of charging data for legal liability is one of the issues here dealt with. When possible, data are collected from multiple sources (e.g. the charging station and the Electric Vehicle) and from different parties with conflicting interests for validating data and breaking data silos that are within the car, the charging stations and the Battery Management System.

The existing policy for greenhouse gas (GHG) abatement aims at decarbonisation of the power sector. The interrelations between the power sector and other economic sectors raise a question of whether the GHG emission reduction policy in the power sector is as effective as it is claimed. Consequential life cycle assessment (CLCA) has been developed to assess the environmental impacts of any industrial/productive sector in relation with changes in the policy and its indirect impacts on other economic sectors. This review is conducted on CLCA studies in the power sector in terms of system boundaries expansion and socio-economic interactions and the ability to quantify indirect environmental impacts. It is indicated that CLCA expanded the system boundaries by applying mutatis mutandis assumption to include several affected products with various scales of change. Economic modelling tools are frequently applied to make assumptions on the extent of change. The applications of these tools also help to identify the environmental profile of product systems and the socio-economic changes such as economic growth and consumer behaviours. Thanks for the expansion of system boundaries and inclusion of socio-economic interactions, the total environmental impacts of power sector are comprehensively quantified. The variations of the total environmental impacts, with different magnitude of change, were observed in several reviewed case studies. In term of GHG emissions, some products become cleaner, for example battery; however, in most of the cases, the power system in general becomes more polluted when indirect impacts on other economic sectors are included.

This study presents how to improve the short-term forecast of photovoltaic plant's output power by applying the Long Short-Term Memory, LSTM, neural networks for industrial-scale solar power plants in Vietnam under possible curtailment operation. Since the actual output power does not correspond to the available power, new techniques (Global Horizontal Irradiance - GHI interval division, P/GHI factor addition (P - Power)) have been designed and applied for processing errors and missing data. The prediction model (LSTM network, structure of hidden layers, number of nodes) has been developed by the authors in a previous work. In this new version of the model, the training technique is improved by using validation and experiments to determine the appropriate relevant parameters. The forecast results show that the proposed new method is more efficient than the old method, as the MAPE (Mean Absolute Percentage Error) forecast error is reduced by 6.059% and the RMSE (Root Mean Square Error) is reduced by 6.710%.

Energy Communities (EC) are a promising solution to reduce both the carbon footprint and the impact of Renewable Energy Sources (RES) on the distribution grid. Based on a simple energy sharing principle, EC can be decisive in the next future energy transition of some problematic territories, like small islands not supplied by the main power grid. By integrating Battery Energy Storage Systems (BESS), it is possible to improve the EC performance. However, due to the still high BESSs unit prices, the goal of this work is to find the optimal size of BESSs, under various conditions, which combines the need to maximize shared energy and the possible revenue of EC actors. To set this multi-objective problem, in this paper is presented a procedural algorithm, numerically implemented in MS Excel environment and optimized through GRG nonlinear algorithm of MS Excel Solver. The algorithm is applied to the case study of Pantelleria island.

Energy production from distributed renewable power plants underwent a takeoff in last years as never before. Nevertheless, the installation of technologies based on variable energy resources and their connection on transmission power lines might cause congestions due to the transmission capacity limits. This paper describes the modelization of a HV transmission line with local renewable production and its optimal management through an Energy Hub model. Aim of the study is to identify the optimal size of the power storage, based on an electoryzer, a hydrogen storage and a fuel cell, in order to minimize the congestion risks and to maximize the exploitation of renewable energy production.

For the participation in the frequency control of the system, power converters can be controlled with different strategies and methods, sharing the common concept of virtual inertia capability. In this work, a sensitivity analysis of two main categories of converter controls with virtual inertia is presented. The considered schemes are a grid-following current vector control with additional virtual inertia block and a grid-forming control scheme based on virtual synchronous machine concept. A proper basis for the comparison is first assessed providing an analytical correlation between the control parameters of the two schemes. For the two control strategies, the sensitivity analysis of the most relevant factors is performed on the linearised model of the system. Time-domain simulations are also performed on the full non-linear model, investigating the frequency dynamics of the two control structures under different oscillating conditions. The analytical comparison and the results of the analyses indicate specific and distinct oscillatory characteristics of the examined control structures, pointing out for each of them opportunities and limitations for participation in the frequency dynamics of the system.

The study (a) assesses the life cycle energy consumption and air emissions impacts of battery electric buses (e-buses) and conventional buses operated in Vietnam, and (b) compares them with those of hydrogen buses. The results indicate that e-buses and hydrogen buses are preferred options compared to conventional buses in terms of energy consumption, GHG emissions and other air quality impacts over their whole life cycle. Life cycle energy consumption of diesel buses is triple that of e-buses, and is significantly higher than that of hydrogen buses. Replacing conventional buses with e-buses can reduce energy consumption by 50%. For GHG emissions and air quality impacts, the adoption of electric and hydrogen mobility in replacement of conventional buses will reduce GHG emissions by 39%, and other impacts related to air quality by 13% to 90%.

The energy transition towards efficient energy production, transport, and use, renewable energy (RE) technologies and innovative energy management brings benefits to reducing greenhouse gas (GHG) emissions and achieving climate targets. The transition requires resources, minerals, metals, and materials for RE technologies themselves, for example, solar photovoltaics (PV), hydrogen fuel cell vehicles (HFCVs) as well as innovative supporting technologies for variable RE, for example, energy storage systems (ESSs). This requirement of resources and materials occurs over the whole supply chain of the technologies, from the extraction of resources, the manufacture of technology, and the deployment of technology, till the very end of its life cycle. In such context, the consideration of resources in general and critical raw materials (CRMs) in particular and their relations to the risk of supply chain disruption are highly important for achieving the global green energy transition. This editorial paper provides a brief view of the close connectivity between materials/resources and the green transition over the whole supply chain of energy technologies.

In this paper, a new low-cost device is proposed for fault location in power distribution system. The device is part of a system that should include several units installed in couples at the two ends of medium voltage (MV) cable lines. Their low cost justifies a widespread installation of these devices, moreover other functionalities could be considered so as to enrich the potential of the system for MV cables monitoring and asset management. The system exploits a two-end traveling wave technique, low complexity, and low-cost solutions both for the analog front end as well as for the communication infrastructure. A LoRa network is indeed considered as wireless modulation technique perfectly suited when communication links with three characteristics are needed: low power, low bit rate, and long range. This paper shows the device that has been set up in Prysmian Electronics with some experimental phases showing the effectiveness of the proposed solution and the further developments expected.

The operation of a power system with 100% converter-interfaced generation poses several questions and challenges regarding various aspects of the design and the control of the system. Existing literature on the integration of renewable energy sources in isolated systems mainly focuses on energy aspects or steady-state issues, and only a few studies examine the dynamic issues of autonomous networks operated with fully non-synchronous generation. A lack of research can be found in particular in the determination of the required amount of grid-forming power, the selection of the number and rated power of the units which should implement the grid-forming controls, and the relative locations of the grid-forming converters. The paper aims to address those research gaps starting from a theoretical point of view and then by examining the actual electrical network of an existing island as a case study. The results obtained from the investigations indicate specific observations and design opportunities, which are essential for securing the synchronization and the stability of the grid. Possible solutions for a fully non-synchronous operation of autonomous systems, in terms of dynamic characteristics and frequency stability, are presented and discussed.

Demand side aggregation represents an important opportunity for ancillary services provision due to the potential that the coordinated management of distributed resources has on affecting power systems' operation. In this framework, the Aggregator has a main role and takes on different relationships with the other actors of the power system, usually becoming a mediator between the prosumers and the distribution system operator. The DEMAND project introduces a new point of view in demand side aggregation by proposing a new framework where the Aggregator is no more needed and prosumers can share and combine their flexibility in a new aggregation platform called Virtual Aggregation Environment (VAE). In this paper, an algorithm for the day- ahead estimation of each prosumer's flexibility is presented. The algorithm evaluates various couples of power variation and desired remuneration to send to the VAE for further elaborations. A case study shows how the algorithm works.

Vietnam energy demand is currently growing at a very high annual rate, with the government being very interested in investments in renewable energies. Since the region with the highest solar and wind potential is far away from the big load centers, an investigation of offshore energy resources is here proposed. In this study, a review of previous energy potential assessments is provided. Moreover, the minimum feed-in-tariff to make the investments profitable is evaluated, showing that the current tariff for offshore wind plants is largely unattractive.

The paper deals with the modelling and simulation of a Fast Discharge Unit (FDU) for quench protection of the Toroidal Field (TF) magnets of the Divertor Tokamak Test, an experimental facility under design and construction in Frascati (Italy). The FDU is a safety key component that protects the superconducting magnets when a quench is detected through the fast extraction of the energy stored in superconducting magnets by adding in the TF magnets a dump (or discharge) resistor. In the paper, two different configurations of dump resistors (fixed and variable respectively) have been analysed and discussed. As a first result, it is possible to underline that the configuration with variable dump resistor is more efficient than the one with a fixed dump resistor.

The PEA method is currently widespread used for space charge measurements in mini-cables in order to qualify the behavior of semicon-dielectric-semicon compound under electric and thermal stress. The main goal of this research is to quantitatively evaluate the relationship between the thermal boundary conditions applied to cables or mini-cables and the maximum local electric field due to the accumulated space charge. Hitherto, several research groups have obtained thermal gradients over the dielectric's radius heating the conductor by Joule effect due to an induced current. In this paper, a numerical approach is offered to calibrate the heat exchange boundary conditions to apply to a sample during PEA space charge measurements. This method aims to reproduce in mini-cables the same operative electric field levels reached in full size HVDC cables.

Under DC stress, the space charge accumulation is believed one of the most responsible of dielectrics ageing. For this reason, due to the increase of the HVDC transmission, a recommendation has been proposed. The latter want to introduce the space charge measure, with the PEA method, in cable specimens during the prequalification or type tests. Considering the several issues related to this kind of measures the aim of the proposed work is find a measurement setup for mini cable specimens which is able to provide a clear and clean space charge profile. Therefore, different tests have been made in this work. In particular, the length of the cable specimen, the width of the pulse electrodes, as well as the distance between the pulse electrodes position and the cell measuring point, have been evaluated. Measurement results shown that the best solution is for a mini cable 2 m length and when the pulse electrodes width and its distance from the measuring point is equal to 20 cm.

The paper proposes a methodology to assess the potential impact of salinity gradient power technology in urban contexts. The idea to employ such energy source in urban contexts derives from the observation that, among the energy districts outputs, low-salinity treated wastewater can be used to produce electricity if a suitable source of high salinity feed (seawater of a salt-works) is also available. The methodology uses the HOMER software for assessing the district’s electric energy production, consumption and exchange with the main grid. Then, starting from the total gross surface and the number of inhabitants of the district, some possible realistic scenarios characterized by different wastewater flow rate are defined. Finally, for each scenario the size and the yearly energy production of the salinity gradient power system are calculated thanks to a simulator carried out by the same authors. An application example, considering three different scenarios, shows that urban density plays a crucial role in the process and that the most promising realistic scenarios are those including treated wastewater and brine and unlimited seawater and brine. The economic feasibility of the salinity gradient power technology is evaluated by a comparison with classical renewable technologies such as photovoltaic and wind systems.

In this work, the minimum losses optimal power dispatch problem for islanded microgrids with distributed energy resources (DER) is solved by means of a distributed heuristic approach. Optimal power management is performed almost in real time, with a predefined schedule, i.e. every 5 min, and the solution is applied to generators when the current operating solution violates voltage or current constraints or when the current configuration produces too large power losses. The operating point of both inverter-interfaced generation units as well as rotating production systems can be modified simply using local information. The latter are voltage measurements and power injections or loads data of local and nearby nodes, therefore information processed at each bus derive from communications between adjacent nodes. The distributed algorithm is iterative but also fast and easy to understand, since it is based on the use of power flow equations. It can be employed for small and medium size networks showing tens of nodes and test results prove that convergence happens in few iterations.

Blockchain technology has found several innovative applications in the electricity industry. However, its potential has still to be discovered. This is partly due to the role that regulation plays in electricity markets. To be introduced, experimented with, and eventually adopted on a commercial scale, blockchain-supported innovations need to fit the existing regulatory framework or the rules to be reshaped or updated. We focus on energy regulators' possible responses to the blockchain-enhanced market operations (both from the incumbents and potential newcomers), suggesting a monitoring mechanism that can support innovation.

The paper presents a study, conceived within the GEYSER FP7 co-funded European research project, on the ancillary services that Green Data Centres (GDCs) can provide, focusing, in particular, on spinning reserve. More in detail, the main contribution of the paper is to show how GDCs can be involved in the secondary frequency regulation process of a smart distribution grid, for contrasting the disturbing effects of unexpected variation of the energy production. With this aim, a real data centre, owned by Engineering S.p.A., is simulated as connected to the Medium Voltage IEEE 14-bus test grid where some RES-based generators are supposed to exist. Simulations are carried out in order to evaluate the impact of power management actions to be executed by the data centre during under-frequency transients, due to an event of renewable energy facilities power production decrease. During this event, the effects of the spinning reserve provided by the data centre are deeply analysed.

In the last decade, remarkable developments have concerned the methods of space charge measurement in the field of insulation systems diagnostic. In particular, methods based on acoustic and thermal phenomena have been largely used. The present review provides a broad overview on the different techniques used describing, for each of them, the working principle, the main features and the most relevant applications. Further details are provided for the Pulsed Electro-Acoustic (PEA) method, as it seems to be the most used. This article provides more details on its historical evolution, showing evidence for its technological limits and taking into consideration the advantages and drawn from the different configurations of the measuring cell. A similar approach has been used for the group of thermal methods, whereas for the optical methods only the basic working principle and latest applications are reported.

The reduction of the inertial response of the generation system has been one of the main obstacles to the penetration of high sharing of renewable energy sources in islanded systems. This issue can be solved thanks to innovative control that makes wind turbines able to provide the so-named synthetic inertia. The paper investigates some scenarios with different levels of wind power penetration in a small island whose grid is not supplied by the main grid, by the use of the software NEPLAN 360, simulating the wind power plants accordingly to the standard IEC 61400-27. The aim of the paper is to assess the maximum level of penetration in the island of wind generation, with traditional control systems, that does not threaten the stability of the system.

Renewable Energy Sources are posing critical issues related to the mining of power systems stability, essentially due to a decrement of the inertial response during system's contingencies. As a consequence, to preserve the security and the reliability of the system, it is necessary to adopt new frequency adjustments mechanisms. This issue becomes particularly critical in isolated power systems, like those of small islands not supplied by the main grid, in the case of high shares of production from unpredictable renewabies such as photovoitaic and wind sources. In this framework, the present work deals with the analysis of the variation of the inertia time constant of a small island in various scenarios characterized by a different share of renewable energy. The study represents the first step of a more extended feasibility study for the conversion of a traditional power system based on fossil fuel towards a renewable energy-based power system.

The paper presents the analysis of some potentially suitable actions for reducing the energy losses of an islanded Medium Voltage distribution network, with the aim of improving electricity distribution efficiency. For this purpose, four actions are considered: 1) increasing the network's rated voltage; 2) reactive power compensation through static capacitor banks; 3) reactive power compensation through switchable capacitor banks; 4) installation of distributed photovoltaic (PV) generation. The first two measures are typically taken into account by the distribution system operators and can be examined by means of classical design methods, whereas the latter two more innovative actions are tested here using specialized software based on the NSGA-II multi-objective optimization algorithm. The fourth action, expanding distributed PV generation, can be motivated through public or private incentives. It is investigated here using an innovative approach to the optimization problem formulation considering the perspectives of both the utility and the consumer. A case study on a small Mediterranean island real existing network is also presented.

In this paper, an original formulation of the control problem for optimal PV array reconfiguration, following a Total Cross Tied layout, is proposed. The formulation follows the well-known subset sum problem, which is a special case of the knapsack problem. The reconfiguration is a measure devoted to mitigate the mismatch effect and maximize the output power of small photovoltaic plants under non-homogeneous working conditions. Therefore, reconfiguration means changing the connections of the solar panels adaptively by a dynamic switching matrix. The control system implements an easy dynamic programming algorithm to change the switches layout. The use of the Munkres assignment method in a post-processing module makes the algorithm able to obtain the optimum configuration for which it is possible to balance and minimize the aging of the switches within the switching matrix.

The “Smart Cities & Communities Initiative” of the Strategic Energy Technology Plan is the strategic European response to lead cities and regions to a carbon free future. In this contest energy efficiency in buildings has a crucial role and must be considered in a holistic approach to the urban planning. In order to implement the minimum requirements stated by the European Directive about the Energy Performance of Buildings, and in order to consider different planning layers with the view to a smart city planning, local regulations are a key factor aiming at sustainable territorial planning. This paper investigates the possibility to draft a basic structure of Municipal Building Regulations in order to guide local administrators and technicians and to limit discretionary power of bureaucracy. The paper is organized as follows. First, a review of the most common practices for building regulations in Europe is proposed, then the basic structure of a municipal building regulation for the city of Palermo (Southern Italy) accounting for sustainability is discussed.

The paper presents a method for the study of large interconnected earthing systems in High Voltage networks. The mathematical model proposed for calculating the distribution of the Single-line-to-Earth fault current is useful for a methodical and accurate analysis of complex systems having meshed configuration and more sources, and has practical application for the Transmission System Operator. Two case studies are provided. The first one considers a fault occurring inside and outside a station in a real 220 kV transmission network. In the second example, the proposed methodology is compared with the classical “Double-sided elimination” method.

Islanded microgrids are small networks that work independently from the main grid. The frequency and voltage in islanded microgrids are affected directly by the output power of distributed generators and power demand variations. In this work, a real-time driven primary regulation, which relies on optimized P-f droop coefficients, is proposed. In all operating conditions, it minimizes the power losses for islanded microgrids. The proposed configuration will allow the optimization modules to interact with each other and adjust parameters producing a suitable power sharing among generators. The methodology is tested based on a hardware-in-the-loop experimental set-up where distributed generators are connected to a group of loads. A parametric analysis is implemented for verification of the effectiveness of the proposed configuration as well as the improvement of the system reliability.

This paper describes the possibility to use the blockchain technology for load and generation aggregation in a new distributed Demand Response (DR) service and customers remuneration system. The blockchain technology and the use of smart contracts for DR allow the creation of a distributed system in which customers can communicate directly, in a transparent, secure and traceable way, with the grid operator to provide their flexibility. In this paper, the DR problem formulation takes into account several aspects, which are periodically executed. First, the blockchain records customers’ energy consumption or production, then, the smart contract starts calculating the baseline and the potential support provided by each customer to fulfil the requested load adaptation. Customers’ availability for generation and load profile modulation is also taken into account, as well as their privacy and an updated definition of the roles of grid and market operators in a new Demand-Response scenario supported by the blockchain technology. The blockchain used is Hyperledger Fabric, since it turned to be flexible for smart contracts implementation while supporting multi-tenancy. Results show the possibility to successfully apply the blockchain technology to this particular topic, even considering privacy-preserving issues.

Cable manufacturing industries are constantly trying to improve the electrical performance of power cables. During the years, it was found that one of the most relevant degradation factors influencing the cable lifetime is the presence of space charge in the insulation layer. To detect the accumulated charge, the pulsed electro-acoustic (PEA) method is the most used technique. Despite the wide use of the PEA cell, several issues are still present. In particular, the PEA output signal is strongly disturbed by the acoustic waves reflections within the PEA cell. This causes the distortion of the output signal and therefore the misinterpretation of the charge profiles. This, in turn, may result in an incorrect cable characterization from the space charge phenomenon point of view. In 2017, due to the proved degradation effect of the space charge accumulation phenomenon, the IEEE Std 1732 was developed. This standard describes the steps to be followed for the space charge measurement in cables specimens during pre-qualification or type tests. Therefore, cable manufacturing industries started to take a particular interest in these measures. In the light of this, the aim of the present work is to highlight that the enacted standard is not easily applicable since various problems are still present in the PEA method for cables. In particular, in this work, the effect of multiple reflected signals due to the different interfaces involved, but also the effect of the signal attenuation due to cable dielectric thickness, as well as the effect of the PEA cell ground electrode thickness in the output charge profile, are reported. These issues have been demonstrated by means of an experimental test carried out on a full-size cable in the Prysmian Group High Voltage laboratory. To better understand the PEA cell output signal formation, a PEA cell model was developed in a previous work and it has been experimentally validated here. In particular, simulations have been useful to highlight the effect of the reflection phenomena due to the PEA cell ground electrode thickness on the basis of the specimen under test features. Moreover, by analyzing the simulation results, it was possible to separate the main signal from the reflected waves and, in turn, to calculate the suitable ground electrode thickness for the cable specimen under test.

This paper describes some critical issues arising during the partial discharge (PD) testing of a 500m delivery length of an XLPE-insulated MV cable. At first, conventional PD measurements were performed on the whole length by using a standard acquisition system; PDs activity was detected, but the system allowed the operator to localize the PDs only on a length of 70 m. A visual inspection of this section highlighted the presence of an excoriation in the outer sheet. Aiming at a more accurate pin-pointing of the defect, more measurements were carried out in the proximity of the outer defect using a portable PD detection system. These measurements showed PDs activity, whose source was located and identified as consisting in internal defects on the inner semicon in proximity of the external excoriation. This proves how PD detection portable instruments are able, in cases like this, to locate the PD source and provide indications for its correct classification.

In this paper, an optimal power dispatch problem on a 24-h basis for distribution systems with distributed energy resources (DER) also including directly controlled shiftable loads is presented. In the literature, the optimal energy management problems in smart grids (SGs) where such types of loads exist are formulated using integer or mixed integer variables. In this paper, a new formulation of shiftable loads is employed. Such formulation allows reduction in the number of optimization variables and the adoption of real valued optimization methods such as the one proposed in this paper. The method applied is a novel nature-inspired multiobjective optimization algorithm based on an original extension of a glowworm swarm particles optimization algorithm, with algorithmic enhancements to treat multiple objective formulations. The performance of the algorithm is compared to the NSGA-II on the considered power systems application. © 2005-2012 IEEE.