1,720,988 research outputs found
A Comparative Study of Ladder Differential Power Processor and Bypass Diode under Partial Shading Conditions
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Demand response of an Electric Vehicle charging station using a robust-explicit model predictive control considering uncertainties to minimize carbon intensity
Full text linkThis paper presents a novel approach to address uncertainties and enable demand response in Electric Vehicle (EV) charging station optimization. A two-stage optimization strategy is proposed, integrating Robust Optimization and explicit Model Predictive Control (eMPC). The first stage involves day-ahead planning using Robust Optimization technique to limit the hourly power consumption of EVs, considering worst-case scenarios caused by uncertainties in EV consumption and CO2 emissions. The objective is to minimize environmental impact by reducing CO2 emissions. An Explicit Model Predictive Control strategy is developed in the second stage for real-time operation. The explicit solution, calculated offline, models uncertainties such as the initial state of charge of the battery energy storage, photovoltaic power production, and EV power consumption. During real-time operation, the explicit solution is accessed using measured data from the charging station, refining the schedule derived from the first stage. The proposed solution is implemented and evaluated at an EV charging station in Trieste, Italy. The results demonstrate a significant 69% reduction in CO2 emissions compared to a deterministic approach while maintaining a real-time computation time of less than 0.1 s
General Rules and Safety Guidelines for a Battery Energy Storage and Photovoltaic System Framework in Commercial and Industrial Installations
No full textThis paper examines the diverse functionalities of Battery Energy Storage Systems (BESS) in Commercial and Industrial (C&I) settings, particularly when integrated with Photovoltaic (PV) systems (C&I PV-BESS). While these systems provide significant benefits in energy efficiency and sustainability, they also introduce concerns regarding fire safety. To address these risks, this study reviews the associated safety hazards and conducts a comprehensive comparison of major international standards aimed at mitigating fire hazards in C&I PV-BESS installations. Additionally, the paper outlines best practices for system installation and management, focusing on key safety aspects such as cell design, module and rack construction, operational protocols, fire suppression systems, and manufacturing processes. Despite the ongoing challenge of establishing universally adopted fire prevention standards for C&I PV-BESS, this paper proposes practical guidelines to enhance safety in these installations. It also highlights innovative solutions to improve the safe operation and long-term reliability of these integrated systems
Active power control of a PV generator for large scale photovoltaic power plant without energy storage
No full textThe increasing renewable energy penetration together with the price reduction of photovoltaic modules is supporting the development of photovoltaic power plants connected to the medium and low voltage grid. Many concerns are emerging about the electrical system stability when it is connected to renewable sources. Usually, photovoltaic power plants are thought to reach always the maximum power point and to extract the maximum power available. However, due to the new grid codes as the ones from Puerto Rico and South Africa, the photovoltaic power plants should not always extract the maximum power available. Instead it is necessary to follow a fix reference due to power curtailment, power reserve or ramp rate. Thus, this article proposes a control method to comply active power requirements by modifying a tracking algorithm. For this purpose, a photovoltaic generator is modelled and controlled in DIgSILENT PowerFactory. The results show that the control proposed can follow a given active power reference despite the ambient conditions
Fully Integrated Optical-Electrical-Thermal Model of Bifacial Photovoltaic Modules for Energy Yield Assessment
No full textBifacial photovoltaic modules represent an emerging technology able to increase the electricity generation from solar energy thanks to their ability to harvest sunlight from both the front and rear surfaces. As the installations of bifacial modules become more and more widespread, even in new and innovative applications, the need for accurate dynamic simulation tools to predict their performance is of the utmost importance. This research presents an advanced coupled optical-electrical-thermal model for the bifacial module dynamic simulation and makes use of the aforementioned model to perform sensitivity analysis intended to determine how several parameters correlated to the bifacial module power output affect the energy yield. Specifically, the annual energy yield of the south-facing bifacial photovoltaic module was assessed focusing on changes in tilt angle and albedo. Three distinct locations across Italy, characterized by different latitudes and climatic conditions, were selected as case studies. The impact of tilt angle on global irradiance received by both the front and rear sides of the bPV module is highlighted, with the sensitivity analysis ranging from 0° to 90° in increments of 10°. Additionally, three albedo values were examined to assess their influence. This study identifies novel results, including local power peaks in rear-side power-time curves at high albedo values and significant variations in optimal tilt angles compared to monofacial optimal values
Network Resilience and Sustainability: Renewable Energy-Based Solutions
Full text linkWith the increase in popularity of mobile services, radio access network (RAN) sustainability and resilience to power outages are becoming primary challenges. This article proposes to use power supply solutions based on renewable ener-gy sources (RESs) to jointly increase RANs' resil-ience and sustainability. We provide an overview of common RAN sustainability practices and pres-ent recent data on the increase in communication network failures. We discuss the concept of resil-ience in RANs, alongside the strategies and challenges of using RESs for power supply. Although RESs integration with RANs has been extensively studied in the literature for sustainability, the operational aspects before, during, and after emergen-cies remain unexplored. This article addresses this gap by evaluating the impact of RESs on the RAN sustainability and resilience through the use of real data from base station (BS) traffic load, grid power outages, and photovoltaic (PV) power production. Our findings show that integrating small PV panel capacities significantly reduces the carbon footprint of RANs, and it is crucial to maintain network operations during outages, especially during daylight hours when PV production is at its peak
Design of an Embedded Test Bench for Organic Photovoltaic Module Testing
No full textIn this article, a multipurpose embedded system for testing organic photovoltaic modules is presented. It is designed to include all the features for real-time monitoring, data acquisition, and power conversion based on a & Cacute;uk converter, providing useful data for scientific investigation of the outdoor operation of organic photovoltaic modules. The embedded system allows both the scan of the I-V curve and the continuous operation of the organic photovoltaic module, such as at its maximum power. Voltage and current at the terminals of the organic photovoltaic module under test and up to four temperatures are continuously measured and stored on a Secure Digital card. The communication interface allows the embedded system to connect with other instruments, such as irradiance sensors, with digital serial output. The embedded system is designed both for laboratory and in-the-field use: it can be powered either by the AC electrical grid or a battery, which can also operate as a backup battery. Galvanic isolation divides the embedded system into the field-side and the logic-side functional sections, providing improved noise immunity and safe operation. The main power distribution system within the embedded system is a +9 V bus; ultra-low-noise linear low dropout regulators provide the +3.3 V and +5 V regulated voltages to supply the analog and digital circuits within the logic-side section, and a flyback converter supplies the field-side section of the board. The proposed embedded solution is validated using an experimental setup built at SolarTechLab, Politecnico di Milano. The experimental results report the feasibility of the proposed embedded system
Resilient design of photovoltaic and battery energy storage systems for telecommunication towers
No full textLAUREA MAGISTRALEL’Europa sta vivendo un aumento della frequenza e della gravità dei fenomeni naturali
legati al cambiamento climatico, come forti venti, inondazioni e temperature estreme,
che colpiscono in modo significativo le infrastrutture elettriche a bassa, media e alta
tensione. Questi eventi hanno un impatto su abitazioni, imprese e, in particolare, sulle
torri di telecomunicazione, il cui funzionamento è cruciale durante le emergenze. Questa
tesi propone soluzioni resilienti e sostenibili per garantire la continuità del servizio in
queste torri, utilizzando energie rinnovabili e sistemi di accumulo a basse emissioni di
carbonio. Pertanto, lo studio propone una metodologia per fornire una valutazione del
rischio, una priorizzazione delle stazioni base di telecomunicazione e un quadro per of-
frire una fornitura energetica affidabile. Questa metodologia viene applicata in un’area
soggetta a inondazioni in Italia. Le torri di telecomunicazione critiche vengono identi-
ficate in base alla loro posizione, alla copertura che forniscono e alla loro importanza
strategica per la comunicazione locale. Successivamente, viene progettato un sistema
energetico dedicato, che combina impianti fotovoltaici con batterie, tenendo conto delle
normative di sicurezza elettrica, dell’ombreggiamento e della superficie utile disponibile.
Nei casi in cui l’installazione dei pannelli non sia possibile, l’opzione si basa esclusiva-
mente sull’utilizzo di batterie. Infine, viene effettuata un’analisi tecnica ed economica
del progetto proposto, valutando la capacità energetica necessaria per coprire interruzioni
prolungate dell’alimentazione elettrica e le condizioni specifiche della regione. I risultati
mostrano che le soluzioni progettate aumentano significativamente la resilienza delle torri
ai guasti elettrici, con un impatto ambientale ridotto rispetto ai generatori tradizion-
ali. Questo approccio può essere replicato in altre aree vulnerabili, fornendo un quadro
sostenibile e scalabile per la gestione delle infrastrutture criticheEurope is experiencing an increase in the frequency and severity of natural phenomena
linked to climate change, such as strong winds, floods, and extreme temperatures, which
significantly affect low, medium, and high-voltage electrical infrastructure. These events
impact homes, businesses, and, in particular, telecommunication towers, whose operation
is critical during emergencies. This thesis proposes resilient and sustainable solutions
to ensure service continuity in these towers, utilizing renewable energy and low-carbon
energy storage systems. Therefore, the study proposes a methodology to provide a risk
assessment, telecommunication base station prioritization, and a framework to offer a re-
liable energy supply. This methodology is applied in a flood-prone area in Italy. Critical
telecommunication towers are identified based on their location, the coverage they pro-
vide, and their strategic importance for local communication. Subsequently, a dedicated
energy system is designed, combining photovoltaic installations with batteries, taking
into account electrical safety regulations, shading, and the available usable area. In cases
where panel installation is not feasible, the option is based exclusively on batteries. Fi-
nally, a technical and economic analysis of the proposed design is performed, evaluating
the energy capacity required to cover prolonged power supply interruptions and the spe-
cific conditions of the region. The results show that the designed solutions significantly
increase the resilience of the towers to electrical failures, with a reduced environmental
impact compared to traditional generators. This approach can be replicated in other
vulnerable areas, providing a sustainable and scalable framework for managing critical
infrastructur
Active Power Control of a PV Generator for Large Scale Photovoltaic Power Plant
Full text linkControllo di potenza attiva per impianti fotovoltaici di grande taglia senza energy storage. Descrizione dei grid code requirements, tendenze attuali mercato voltaico. Descrizione modello cella fotovoltaica, modello dell'inverter e del suo controllo. Algoritmo modificato per taglio di potenza attiva con valore fisso di potenza. Analisi economico-comparativa tra una soluzione con energy storage e senza energy storage per il taglio di potenza attiva.ope
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