Search results for "elettrici"
showing 10 items of 959 documents
Extending the Power Range of a Solar Inverter
2018
Solar inverters feature a minimum and maximum limit of the maximum power point voltage. Overcoming these limits leads to a disconnection of the power equipment, thus wasting the solar energy. In this paper, a solution to extend the power range of a solar inverter is presented. The proposed solution extends he minimum maximum power point limit of a commercial solar inverter by means of a battery energy storage system, including a DC/DC power converter. The battery energy storage system is connected in series to the photovoltaic module. If the photovoltaic module voltage drops below the minimum maximum power point limit, the battery energy storage system is enabled thus boosting the input vol…
A study on the assessment of the production costs curves in micro-grids
2013
In micro-grids, due to their small scale, there is commonly only one power supplier. A competitive wholesale market hardly exists, so the question about how to consider market issues for small producers within micro-grids arises. On the other hand, the specific features of micro-grids where load and generated power hardly find a balance, require that customers take part to regulation issues, also using demand-response (DR) programs. In this paper, price responsive (PR) policies and their programs are discussed to answer this question. A case study of a micro-grid with one micro-turbine and two photovoltaic (PV) generators is analyzed to assess the overall production cost in order to build a…
Electrical Safety Analysis in the Presence of Resonant Grounding Neutral
2019
The resonant grounding is one of the possible methods of the system neutral grounding for the medium voltage distribution. IEEE standards do define this grounding configuration, but important advantages and drawbacks of the resonant grounding might not be fully known, due to its rather uncommon application in North America. On the other hand, resonant grounding in Europe is imposed by the increased requirements for power quality, especially for medium-voltage (MV) industrial users, imposed to electric utilities by regulatory authorities, with the purpose to protect the interests of users and consumers. Level of the continuity of the service, magnitude and phase of ground-fault currents, mag…
Forensic Analysis of Fire in a Substation of a Commercial Center
2020
In this article, the authors discuss the legal liabilities of the professional engineer as both the engineer of record of a project and the construction site manager. In particular, this article analyzes the case of a fire at the end-user medium voltage–low-voltage (MV–LV) substation of a shopping center in Italy, which occurred a few years after the maintenance works on the electrical installation. The professional engineer who had designed and overseen the construction of the substation was accused of professional negligence. The authors through the examination of applicable technical standards, as well as of safety regulations, demonstrate that the professional engineer had acted diligen…
Improved High-Fidelity IPMSM mathematical model Including Saturation, Cross-Coupling, Torque Ripple and Iron Loss effects
2022
For enhanced control algorithm design purposes, accurate and high-fidelity electrical machine mathematical models are fundamentals. Usually, accurate evaluation of electrical machine behaviour requires finite element analysis (FEA) with consequent high-computational times. This paper presents an improved high-fidelity Interior Permanent Magnet Synchronous Machine (IPMSM) mathematical model including saturation, cross-coupling, torque ripple and iron loss effects. This model has been implemented in Matlab®/Simulink environment and its parameters are implemented by the use of lookup tables. To validate the modelling approach proposed, a comparative analysis between the proposed Matlab®/Simuli…
Impact Evaluation of Innovative Selective Harmonic Mitigation Algorithm for Cascaded H-Bridge Inverter on IPMSM Drive Application
2021
This paper presents a detailed analysis of the use of a novel Harmonic Mitigation algorithm for Cascaded H-Bridge Multilevel Inverter in electrical drives for the transportation field. For this purpose, an enhanced mathematical model of Interior Permanent Magnet Synchronous Motor (IPMSM), that takes into account simultaneously saturation, cross-coupling, spatial harmonics, and iron loss effects, has been used. In detail, this model allows estimating accurately the efficiency and the torque ripple of the IPMSM, crucial parameters for transportation applications. Moreover, two traditional pulse width modulation strategies, Sinusoidal Phase-Shifted and Switching Frequency Optimal Phase-Shifted…
Performance Improvement of Grid-Integrated Doubly Fed Induction Generator under Asymmetrical and Symmetrical Faults
2023
The doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) suffers from voltage and frequency fluctuations due to the stochastic nature of wind speed as well as nonlinear loads. Moreover, the high penetration of wind energy into the power grid is a challenge for its smooth operation. Hence, symmetrical faults are most intense, inflicting the stator winding to low voltage, disturbing the low-voltage ride-through (LVRT) functionality of a DFIG. The vector control strategy with proportional–integral (PI) controllers was used to control rotor-side converter (RSC) and grid-side converter (GSC) parameters. During a symmetrical fault, however, a series grid-side converter…
A Model for the Study of Sheath Currents in Medium Voltage Cables for Industrial Application
2020
In this paper, the implementation of a simulation model for studying the effect of cross-bonding of metallic sheaths and/or non-magnetic armor of single-core medium voltage cables in the same circuit is discussed. With the use of single-core cables, the resistive losses due to the induced circulating currents in cable sheaths or armors causes an increase of cable temperature that reduces its ampacity. In addition, the risk of electric shock due to induced voltages may be present if a person is exposed to the armor/sheath at the unbounded end. For this reason, special bonding techniques are used to significantly reduce these currents. The authors have implemented a model that could be used t…
A Feasibility Study for the Transition to Electric Mobility in the Island of Favignana
2021
The energy transition and climate neutrality are a short time scenario as climate concerns are rising fast. Small islands are natural microgrids in which the energy transition is subjected to economic and regulatory constraints and highly challenged by technical issues. As a first step, the Mediterranean island of Favignana has been considered in this study, to assess how electric mobility could impact the power system. According to the plans from the local decision makers, the island is moving towards a full public electric mobility in the near term, also due to the participation in the BloRin project. For this reason, a feasibility study about the technical and environmental impact of ele…
Cabine secondarie: nodi intelligenti e sicuri delle smart grid
2015
Nel futuro panorama delle Smart Grid, le cabine secondarie assumeranno il ruolo di nodi intelligenti e sicuri della rete di distribuzione, integrando diverse soluzioni innovative di monitoraggio, comunicazione, controllo e richiedendo maggiori caratteristiche di sicurezza come proposto nei due progetti di ricerca REIPERSEI e NewCabElarc