1,720,973 research outputs found
Smart grids for power quality improvement
Full text linkIn the context of an increasing penetration of Distributed Generators, Distribution System Operators of any size are facing the transition to the Smart Grid, investigating how its role will change in the future. This work will present a comprehensive analysis of how a DSO would face the Power Quality issue in the future thanks to the technologies of the smart grids.
The activities have been carried out in collaboration with the DSO of the city of Terni, namely ASM Terni S.p.A. (ASM) and its productivity unit Terni Distribuzione Elettrica (TDE) which owns and manages the distribution network in the municipality. During the work lifespan, there has been the opportunity to evaluate smart technologies and carry out grid analysis in a real environment, notably, the Medium Voltage distribution network of TDE and the living laboratory at ASM headquarters. Some activities have been totally developed within this work whilst others have been carried out in the context of some European projects that have been founded or cofounded by the Innovation and Research & Innovation actions for Energy sector established by the European Commission and involve ASM as consortiums’ partner. The consortiums of these projects have designed, produced and installed in the ASM facilities cutting-edge devices and software solutions for the distribution network and the electrical customers; this work has evaluated their contribution on the power quality.
Considering Smart Grid definition, it is important to understand what is currently Power Quality for a DSO; in this respect, the main objective of a DSO is to reduce the interruptions, secondly abnormal voltages are also an issue as well as the reduction of technical losses (i.e., increasing the energy efficiency). However, DSOs are focused on outages since it means the lack of its main services to the users, namely, electrical energy, which also dramatically affects other crucial services such as Telecommunication, heating, cooling, water, industrial processes.
Moreover, the Italian DSOs, which have been studied in this work, receive monetary incentives or have to pay penalties if the outages, recorded in a year, are less than defined objectives or more than these. Investigating on reduction of outages implies an increase of resilience of the distribution network, as the ability of a DSO to promptly react when a foreseen event and rapidly restore the network to the normal status.
The reduction of outages are investigated in this work considering contributions on the network development plans and on real time operations. Therefore, in a first stage, the analysis of a component widely installed in the Italian distribution networks has been carried out; notably thermal analysis of MV cable and joint is performed in order to investigate on the anomalous number of faults on this component that have been recorded in summer during last years.
Moreover, the distribution network of TDE has been analyzed with a Resilience assessment software and its related procedures for improving and validating the development plan of the distribution network. The homemade software, developed during this work lifespan, can be used for any networks and the resilience can be assessed for any type of treats.
The last stage consists of theoretical evaluations and demonstration activities of innovative solutions that could help the DSO to reduce congestions in the network during real time operation (i.e., to prevent and foreseen outages). The enabling tools that have been used are Real time Smart Meters installed in the networks and proper management software. In this respect, main concern of this work has been the interaction between DSO and Aggregator who manages a pool of users in the Demand Response campaigns. The evaluated mechanisms allow DSO to increase hosting capacity of the network in respect of Photovoltaic plants (PV) and Electrical Vehicles (EV). Moreover, this work presents assessment on cooperation mechanism between DSO and a rural microgrid by means of a proper ICT infrastructure.
In the context of power quality improvement thanks to the Smart Grids, further technologies have been evaluated in this work. With respect to the energy efficiency and voltage control, the support from storage systems have been studied by means of tests on the field, as well as it has been assessed the support from EV charging stations coordinate with the implementation of smart contracts leveraging on blockchain technology
Transition to electric vehicles in a company's fleet. Design and policy on a case study
No full textMany private and public companies are moving towards fleet electrification; this new trend is significantly fostered by public strategies about decarbonization, market conditions and companies' policies for reducing their carbon footprint. Nevertheless, the impact of the electrical fleet on logistics and electrical consumptions has not been extensively evaluated in the literature. This paper aims to assess these impacts considering the data of an existing traditional fleet. The presented model takes into account several parameters and conditions and it validates different policies and design solutions. The results show that the proposed solutions would enable company managers painlessly adopting electric vehicles in their fleets
Moving towards self-consumption and self-sufficiency: COVID-19 impact in the city of Terni
No full textThis paper presents a statistical analysis on producers’ data collected between 2015 and 2020 by the DSO in the city of Terni (Italy). The integration of prosumers with the electrical system is investigated through appropriate indicators, such as self-consumption and self-sufficiency, the case study is placed within the Italian and International scenario and enriched with comments and observations. In particular, effects of Covid-19 pandemic to prosumers’ behaviour are reported, highlighting an increasing of self-consumption by domestic prosumers, in line with the European and national policy
Optimizing EV company fleet management in an energy district
No full textIn the context of the widespread of electrical vehicles and electrical company fleets, this paper investigates optimal strategies for scheduling the charging sessions in an energy district. Indeed, the adoption of charging stations and electric vehicles could dramatically impact the load profiles of private companies, nevertheless, there is an opportunity to consider the vehicle recharge flexible by design. For this reason, the paper shows an optimization model for managing the charging sessions and its application in a real energy district. The presented results were collected after simulating several configuration scenarios, main findings highlight benefits for the operators that could justify the adoption of these strategies on their fleets
Exploiting RES for Hydrogen mobility: a new scenario for the company's fleet management
No full textHydrogen aroused a great interest in the last decades as a promising energy vector for the energy transition as well as renewable energy storage. This article investigates the technical feasibility of a hydrogen-powered fleet, in the context of a microgrid with renewable generation. The hydrogen demand is satisfied through the electrolyser powered by local RES and periodical external refueling of a local hydrogen storage system. The model of the microgrid is implemented in the open-source GNU Octave environment and is exploited to size the local storage capacity. Different types of vehicles were considered and hydrogen pressure levels were distinguished among the system components. The model was applied to the waste collection fleet and the headquarters of ASM S.p.A., a utility located in the center of Italy, chosen as a case study. The dataset of 143 vehicles was used to model the hydrogen-powered fleet. Three scenarios were evaluated: hydrogen production using i) Reverse Power Flow, ii) PV production and iii) electricity drown from the grid. The storage capacity depends on the scenarios and in the case study it ranges from about 35 to 47 m^3 , in comparison with 13.6 m^3 of current diesel refueling system, assuming the same frequency of external refueling
Developing a Decision Support System for Flexibility Management in the Distribution Networks
No full textIn the last years, flexibility markets have been developed in Europe in order to support distribution system operators to manage their systems characterized by a high penetration of distributed generators. The proper exploitation of these market services would require optimization tools for flexibility management as well as proper forecasting tools that could reduce the uncertainty on load prediction. In this context, this work presents a decision support system for flexibility exploitation (DSSFE). In addition, the effects of random behavior of the users and the wrong knowledge of flexibility capability have been assessed. The developed algorithm has been tested on 141 IEEE case study network assuming several distributions of flexibility capabilities. The collected results show that the developed DSSFE is efficient for solving network congestions; nevertheless, conservative approaches in the optimization process are needed in order to take into account the random behavior of the users
Accident Triggered by Electrical Failures in Seveso Sites
Full text linkElectrical maintenance is important for appropriate of Major Accident Prevention Policy MAPP at Seveso sites. At Seveso sites, many accidents include in the causes an electrical failure, due usually to a poor maintenance. Power outages, in particular, originate cascade effects, leading to a possible loss of hazardous materials. The repository of the minor incidents and near misses recorded at Seveso sites is a valuable source for investigating electrical failures, causes, effects and possible prevention and mitigation measures. The present paper discusses a number of incident records, gathered at Seveso establishments, during the mandatory inspections, required by the Seveso Directive. Gathered documents cover different types of plant, including refineries, oil terminal, LPG depots and chemical plants. They have been analysed, using advanced method, including machine learning. The results of this analysis have been exploited to provide the establishments’ operator with a few recommendations, essential to improve electrical safety and prevent major accidents
Electrical Energy Production from Coal: Technical and Economic Performances during the Last Twenty Years
No full textDuring the last twenty years (2000 - 2020) coal was the first fuel for electrical energy production. Even if the global production is decreasing, it has still the highest share in the world energy mix. The paper presents an analysis of the last twenty years of coal production, it analyses the technical indicators (i.e., capacity factor, energy efficiency and emissions) as well as the levelized cost of energy. The presented analysis is based on data publicly available, summing up the actual working conditions of the coal power plants. Main outcomes highlight that actual indicators are significantly lower than rated values; this is mainly due to market conditions that are often unfavorable for production from coal. Finally, the results can be used for adjusting the most recent energy policies, that are going to face new market conditions because of force maj eure events (i.e., Ukraine crisis) as well as decarbonization processes, already developed in many European countries
Risk Assessment in Low Voltage Distribution Networks
No full textThis paper presents a risk assessment methodology developed by Areti S.p.A., the distribution system operator of Rome, Italy, and applied in the more general context of a risk-based planning of low voltage distribution networks. A risk model comprising fault rate and impact analyses is applied to map the risk of the entire LV distribution grid of Rome. The continuity of supply indicator is used as a risk factor in the study. Risk thresholds are also defined with the aim to identify the portion of the grid which requires investments.This paper presents a risk assessment methodology developed by Areti S.p.A., the distribution system operator of Rome, Italy, and applied in the more general context of a risk-based planning of low voltage distribution networks. A risk model comprising fault rate and impact analyses is applied to map the risk of the entire LV distribution grid of Rome. The continuity of supply indicator is used as a risk factor in the study. Risk thresholds are also defined with the aim to identify the portion of the grid which requires investments
Electrical Energy Production from Natural Gas. Technical and Economic Performances during the Last Twenty Years
No full textDuring the last twenty years (2000 - 2020) natural gas was the second fuel for electrical energy production. Even if its availability could be affected by force majeure events because of its geographical distribution, it has still a great share in many countries. The paper presents an analysis of the last twenty years of natural gas production, it analyses the technical indicators (i.e., capacity factor, energy efficiency and emissions) as well as the levelized cost of energy. The work is based on data publicly available, evaluating the actual working conditions of the power plants supplied by natural gas. Main outcomes show that actual indicators are significantly lower than rated values; this is mainly due to market conditions that are often unfavorable for production from coal. Finally, the results can be used for adjusting the most recent energy policies, that are going to face new market conditions because of force majeure events (i.e., Ukraine invasion) as well as decarbonization processes, already developed in many European countries
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