293 research outputs found

    Empirical modelling of the solar spectral influence on photovoltaic devices for improved performance forecasting

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    Photovoltaic performance modelling is essential for the successful development of PV systems. Accurate modelling can inform system design and financing prior to construction, help with fault detection during operation, and improve the grid penetration of PV energy. Whereas the models to account for the effects of broadband irradiance, temperature, and so forth on PV performance are well established, those for the influence of the solar spectrum, known as spectral correction functions (SCFs), suffer a range of limitations. Existing models are typically based on proxy variables used to represent the solar spectrum, which are restricted in the amount of information they contain on the prevailing spectral irradiance conditions. Furthermore, validation of these models is restricted to climates that are not representative of the UK, where a broader range of spectral irradiance conditions is experienced due to its high northern latitude and frequent overcast or partially overcast skies. Some studies have explored the possibility of characterising measured spectra with parameters such as the average photon energy to develop SCFs. However, these studies are limited in terms of their validation scope, such as duration of field data and types of PV module, and extension to a predictive model. In this project, two new SCFs are developed and validated in two distinct climate regions for multiple PV technologies. The first is based on the average photon energy alone (f(APE)), while the second is based on both the average photon energy and the depth of the 650--670nm water absorption band (f(APE,e)). Using data from Go (Golden, Colorado, USA), the former is shown to cut the prediction error for aSi modules by around 40% relative to a single-variable air mass SCF and a double-variable air mass and clearness index SCF. The latter, f(APE,e), addresses issues raised in the literature regarding the reliability of APE as a spectral characterisation index. Using the same data, f(APE,e) is shown to cut the prediction error by up to 60% with respect to a comparable multivariable proxy SCF based on the air mass and atmospheric precipitable water content. These results are also validated at a new test site built at the University of Nottingham as part of this project. Although the overall errors are greater due to site-specific system characteristics, the relative improvements achieved by the APE-based models with respect to the proxy-based models are maintained in both climate regions. The proposed spectral correction approaches can be integrated into wider PV performance models to improve their performance forecasting accuracy

    Redes de sensores para la predicción solar a corto plazo en el marco de las microgrids y smartcities

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    En los últimos años, la potencia fotovoltaica instalada global ha crecido notablemente, llegando a superar el 20\% de la demanda energética en varios países. Esto se debe en parte a la reducción de costes de esta tecnología y la política de promover el uso de energías renovables. La producción de la energía fotovoltaica depende directamente de los niveles de radiación solar incidente sobre los paneles, que se trata de un recurso externo y variable. La irradiancia solar fluctúa principalmente por dos factores, pero la mayor variabilidad está asociada a la presencia de nubes, y estas variaciones tienen una duración que va desde unos pocos segundos hasta varios minutos. Debido al funcionamiento del mercado eléctrico y a la nula inercia en la producción energética de estos sistemas, los productores fotovoltaicos necesitan de predicciones precisas en diferentes horizontes temporales con el fin de maximizar la energía ofertada en el mercado, incrementando de este modo la integración de la misma. Por otra parte, también necesitan datos en tiempo real para una gestión más óptima del sistema fotovoltaico. Las predicciones a corto plazo se emplean para el sistema de control y balance de la producción energética, y a medio plazo para la programación y venta de energía en el mercado eléctrico, sin embargo, los sistemas actuales de predicción son escasos y caros para ser contemplados en sistemas de media y pequeña escala. Numerosos estudios han intentado cubrir la necesidad de predicción a corto plazo estimando espacio-temporalmente el campo de irradiancia con cámaras de cielo completo e imágenes de satélite, sin embargo, estos métodos están limitados por la problemática de la conversión de imagen a irradiancia. Investigadores influyentes en este área creen que las redes de sensores de irradiancia pueden jugar un papel fundamental en este contexto, ofreciendo en tiempo real varias medidas espaciales y con la alta resolución temporal necesaria. La información espacio-temporal capturada por la red permitiría estimar el campo de irradiancia y analizar su evolución, capturando incluso los eventos más rápidos. Las tecnologías inalámbricas han evolucionado en el marco de las ciudades inteligentes y el internet de las cosas, apareciendo tecnologías que se adecuan a diferentes escenarios. El interés mostrado en estos sistemas ha producido un abaratamiento de los módulos de comunicaciones inalámbricas, gracias a la economía de escala. Las redes de sensores podrían beneficiarse de estas tecnologías inalámbricas, ofreciendo a su vez un ahorro en costes del despliegue respecto a su equivalente cableado y una mayor flexibilidad para integrar nuevos nodos en la red. Por ello, esta tesis se pretende estudiar el potencial de estas redes inalámbricas como fuente de información crítica para la gestión a corto plazo de sistemas fotovoltaicos, y la explotación de los datos de la misma, implementando y desarrollando algoritmos con estos datos con fines de predicción de la producción y para la operación óptima de estos sistemas.In recent years, global installed photovoltaic power has grown significantly, exceeding 20% of energy demand in several countries. This is partly due to the cost reduction of this technology and the policy of promoting the use of renewable energies. Photovoltaic energy production depends directly on the levels of solar radiation incident on the panels, which is an external and variable resource. Solar irradiance fluctuates mainly due to two factors, but the greatest variability is associated with the presence of clouds, and these variations range in duration from a few seconds to several minutes. Due to the functioning of the electricity market and the lack of inertia in the energy production of these systems, PV producers need accurate forecasts at different time horizons in order to maximize the energy offered in the market, thus increasing the integration of the same. On the other hand, they also need real-time data for more optimal PV system management. Short-term forecasts are used for the energy production control and balancing system, and medium-term forecasts are used for scheduling and selling energy in the electricity market, however, current forecasting systems are scarce and expensive to be contemplated in medium and small-scale systems. Numerous studies have attempted to address the need for short-term forecasting by estimating the spatio-temporal irradiance field with full-sky cameras and satellite imagery, however, these methods are limited by the problems of image-to-irradiance conversion. Influential researchers in this area believe that irradiance sensor networks can play a key role in this context, providing various spatial measurements in real time and with the necessary high temporal resolution. The spatio-temporal information captured by the network would allow estimating the irradiance field and analyzing its evolution, capturing even the fastest events. Wireless technologies have evolved within the framework of smart cities and the internet of things, with the emergence of technologies that are suitable for different scenarios. The interest shown in these systems has led to a reduction in the cost of wireless communications modules, thanks to economies of scale. Sensor networks could benefit from these wireless technologies, offering savings in deployment costs compared to their wired equivalent and greater flexibility to integrate new nodes in the network. Thus, this thesis aims to study the potential of these wireless networks as a source of critical information for the short-term management of photovoltaic systems, and the exploitation of the data from it, implementing and developing algorithms with this data for production prediction purposes and for the optimal operation of these systems

    Design and Implementation of an Intelligent Safety and Security System for Vehicles Based on GSM Communication and IoT Network for Real-Time Tracking

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    In recent years, the surge in car theft cases, often linked to illicit activities, has become a growing concern. Simultaneously, countries grappling with oil shortages have shifted towards converting vehicles to run on liquid propane gas, presenting new safety challenges for car owners. This paper introduces a novel integrated intelligent system designed to address the challenges of car theft and safety concerns associated with gas-based vehicles. By seamlessly integrating these concerns into a single system, it aims to achieve significantly improved performance compared to traditional alarm systems. The proposed system consists of three primary parts: the car security subsystem, an Internet of Things (IoT)-based real-time car tracking subsystem, and the car safety subsystem. Utilizing key technologies such as the Arduino Microcontroller, Bluetooth module, vibration sensor, keypad, solenoid lock, GSM module, NodeMCU microcontroller, GPS module, MQ-4 gas sensor, flame sensor, temperature sensor, and Bluetooth module, the system aims to provide a comprehensive solution for the mentioned issues. Furthermore, the vibration sensor plays a crucial role in identifying unauthorized vehicle operations. Its significance lies in detecting the vibrations emanating from the running engine. Concurrently, other modules and sensors are utilized for real-time tracking and enhancing vehicle safety. These measures include safeguarding against incidents like fire outbreaks or gas leaks within the gas container. Finally, after assembling the system, a practical test was conducted, yielding favourable performance results. This paper describes a meaningful step towards improving the protection and safety for the cars, simultaneously addressing the stealing prevention and gas-related accident alleviation

    Short-term forecast techniques for energy management systems in microgrid applications

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    A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Sustainable Energy Science and Engineering of the Nelson Mandela African Institution of Science and TechnologyIn the 2015 Paris Agreement, 195 countries adopted a global climate agreement to limit the global average temperature rise to less than 2°C. Achieving the set targets involves increasing energy efficiency and embracing cleaner energy solutions. Although advances in computing and Internet of Things (IoT) technologies have been made, there is limited scientific research work in this arena that tackles the challenges of implementing low-cost IoT-based Energy Management System (EMS) with energy forecast and user engagement for adoption by a layman both in off-grid or microgrid tied to a weak grid. This study proposes an EMS approach for short-term forecast and monitoring for hybrid microgrids in emerging countries. This is done by addressing typical submodules of EMS namely: load forecast, blackout forecast, and energy monitoring module. A short-term load forecast model framework consisting of a hybrid feature selection and prediction model was developed. Prediction error performance evaluation of the developed model was done by varying input predictors and using the principal subset features to perform supervised training of 20 different conventional prediction models and their hybrid variants. The proposed principal k-features subset union approach registered low error performance values than standard feature selection methods when it was used with the ‘linear Support Vector Machine (SVM)’ prediction model for load forecast. The hybrid regression model formed from a fusion of the best 2 models (‘linearSVM’ and ‘cubicSVM’) showed improved prediction performance than the individual regression models with a reduction in Mean Absolute Error (MAE) by 5.4%. In the case of the EMS blackout prediction aspect, a hybrid Adaptive Similar Day (ASD) and Random Forest (RF) model for short-term power outage prediction was proposed that predicted accurately almost half of the blackouts (49.16%), thereby performing slightly better than the stand-alone RF (32.23%), and ASD (46.57%) models. Additionally, a low-cost EMS smart meter was developed to realize the implemented energy forecast and offer user engagement through monitoring and control of the microgrid towards the goal of increasing energy efficiency

    Real-time Volt-Var control of grid forming converters in DER-enriched distribution network

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    The growing installation of distributed energy resources (DERs) in a distribution network (DN) poses substantial issues related to voltage regulation. Due to constrained switching operation and slower response time, traditional voltage regulation devices cannot handle current voltage-related challenges. One alternative to solve these problems is to use smart converters to control the reactive power to regulate the voltage. Volt-Var control (VVC) is one of the simplest approaches for controlling the reactive power from smart converters. Among several converters, grid forming converters (GFCs) are more suitable in DER-enriched distribution networks. Since DER-enriched distribution networks have a higher fluctuation in voltage profile, real-time control is advantageous. Therefore, this work presents an advanced real-time reactive power control for handling voltage violations in a DN using GFC. The uniqueness of this method is that it controls the voltage magnitude of affected nodes by dispatching reactive power from smart converters in real-time. By running cyber-physical co-simulation (CPCS) between the Typhoon HIL 604 and OpenDSS, the Volt-Var control can be done in real time. The grid-forming converter is modelled in Typhoon HIL 604, which acts as a physical layer of the proposed cyber-physical system for real-time VVC. A CIGRE medium voltage distribution network is designed in OpenDSS and serves as one of the parts of the cyber layer. The CPCS between Typhoon HIL and OpenDSS and the control algorithm are both done by a programme written in Python. The execution of the control algorithm is performed in real time using the Supervisory Control and Data Acquisition (SCADA) developed in this study. The real-time simulation shows that the proposed real-time VVC is capable of handling voltage violations in real time in DER-enriched distribution networks

    Electronic Devices for the Combination of Electrically Controlled Drug Release, Electrostimulation, and Optogenetic Stimulation for Nerve Tissue Regeneration

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    [ES] La capacidad de las células madre para proliferar formando distintas células especializadas les otorga la potencialidad de servir de base para terapias efectivas para patologías cuyo tratamiento era inimaginable hasta hace apenas dos décadas. Sin embargo, esta capacidad se encuentra mediada por estímulos fisiológicos, químicos, y eléctricos, específicos y complejos, que dificultan su traslación a la rutina clínica. Por ello, las células madre representan un campo de estudio en el que se invierten amplios esfuerzos por parte de la comunidad científica. En el ámbito de la regeneración nerviosa, para modular su desarrollo y diferenciación el tratamiento farmacológico, la electroestimulación, y la estimulación optogenética son técnicas que están consiguiendo prometedores resultados. Es por ello por lo que en la presente tesis se ha desarrollado un conjunto de sistemas electrónicos para permitir la aplicación combinada de estas técnicas in vitro, con perspectiva a su aplicación in vivo. Hemos diseñado una novedosa tecnología para la liberación eléctricamente controlada de fármacos. Esta tecnología está basada en nanopartículas de sílice mesoporosa y puertas moleculares de bipiridina-heparina. Las puertas moleculares son electroquímicamente reactivas, y encierran los fármacos en el interior de las nanopartículas, liberándolos ante un estímulo eléctrico. Hemos caracterizado esta tecnología, y la hemos validado mediante la liberación controlada de rodamina en cultivos celulares de HeLa. Para la combinación de liberación controlada de fármacos y electroestimulación hemos desarrollado dispositivos que permiten aplicar los estímulos eléctricos de forma configurable desde una interfaz gráfica de usuario. Además, hemos diseñado un módulo de expansión que permite multiplexar las señales eléctricas a diferentes cultivos celulares. Además, hemos diseñado un dispositivo de estimulación optogenética. Este tipo de estimulación consiste en la modificación genética de las células para que sean sensibles a la radiación lumínica de determinada longitud de onda. En el ámbito de la regeneración de tejido mediante células precursoras neurales, es de interés poder inducir ondas de calcio, favoreciendo su diferenciación en neuronas y la formación de circuitos sinápticos. El dispositivo diseñado permite obtener imágenes en tiempo real mediante microscopía confocal de las respuestas transitorias de las células al ser irradiadas. El dispositivo se ha validado irradiando neuronas modificadas con luz pulsada de 100 ms. También hemos diseñado un dispositivo electrónico complementario de medida de irradiancia con el doble fin de permitir la calibración del equipo de irradiancia y medir la irradiancia en tiempo real durante los experimentos in vitro. Los resultados del uso de los bioactuadores en procesos complejos y dinámicos, como la regeneración de tejido nervioso, son limitados en lazo abierto. Uno de los principales aspectos analizados es el desarrollo de biosensores que permitiesen la cuantización de ciertas biomoléculas para ajustar la estimulación suministrada en tiempo real. Por ejemplo, la segregación de serotonina es una respuesta identificada en la elongación de células precursoras neurales, pero hay otras biomoléculas de interés para la implementación de un control en lazo cerrado. Entre las tecnologías en el estado del arte, los biosensores basados en transistores de efecto de campo (FET) funcionalizados con aptámeros son realmente prometedores para esta aplicación. Sin embargo, esta tecnología no permitía la medición simultánea de más de una biomolécula objetivo en un volumen reducido debido a las interferencias entre los distintos FETs, cuyos terminales se encuentran inmersos en la solución. Por ello, hemos desarrollado instrumentación electrónica capaz de medir simultáneamente varios de estos biosensores, y la hemos validado mediante la medición simultánea de pH y la detección preliminar de serotonina y glutamato.[CA] La capacitat de les cèl·lules mare per a proliferar formant diferents cèl·lules especialitzades els atorga la potencialitat de servir de base per a teràpies efectives per a patologies el tractament de les quals era inimaginable fins fa a penes dues dècades. No obstant això, aquesta capacitat es troba mediada per estímuls fisiològics, químics, i elèctrics, específics i complexos, que dificulten la seua translació a la rutina clínica. Per això, les cèl·lules mare representen un camp d'estudi en el qual s'inverteixen amplis esforços per part de la comunitat científica. En l'àmbit de la regeneració nerviosa, per a modular el seu desenvolupament i diferenciació el tractament farmacològic, l'electroestimulació, i l'estimulació optogenética són tècniques que estan aconseguint prometedors resultats. És per això que en la present tesi s'ha desenvolupat un conjunt de sistemes electrònics per a permetre l'aplicació combinada d'aquestes tècniques in vitro, amb perspectiva a la seua aplicació in vivo. Hem dissenyat una nova tecnologia per a l'alliberament elèctricament controlat de fàrmacs. Aquesta tecnologia està basada en nanopartícules de sílice mesoporosa i portes moleculars de bipiridina-heparina. Les portes moleculars són electroquímicament reactives, i tanquen els fàrmacs a l'interior de les nanopartícules, alliberant-los davant un estímul elèctric. Hem caracteritzat aquesta tecnologia, i l'hem validada mitjançant l'alliberament controlat de rodamina en cultius cel·lulars de HeLa. Per a la combinació d'alliberament controlat de fàrmacs i electroestimulació hem desenvolupat dispositius que permeten aplicar els estímuls elèctrics de manera configurable des d'una interfície gràfica d'usuari. A més, hem dissenyat un mòdul d'expansió que permet multiplexar els senyals elèctrics a diferents cultius cel·lulars. A més, hem dissenyat un dispositiu d'estimulació optogenètica. Aquest tipus d'estimulació consisteix en la modificació genètica de les cèl·lules perquè siguen sensibles a la radiació lumínica de determinada longitud d'ona. En l'àmbit de la regeneració de teixit mitjançant cèl·lules precursores neurals, és d'interés poder induir ones de calci, afavorint la seua diferenciació en neurones i la formació de circuits sinàptics. El dispositiu dissenyat permet obtindré imatges en temps real mitjançant microscòpia confocal de les respostes transitòries de les cèl·lules en ser irradiades. El dispositiu s'ha validat irradiant neurones modificades amb llum polsada de 100 ms. També hem dissenyat un dispositiu electrònic complementari de mesura d'irradiància amb el doble fi de permetre el calibratge de l'equip d'irradiància i mesurar la irradiància en temps real durant els experiments in vitro. Els resultats de l'ús dels bioactuadors en processos complexos i dinàmics, com la regeneració de teixit nerviós, són limitats en llaç obert. Un dels principals aspectes analitzats és el desenvolupament de biosensors que permeteren la quantització de certes biomolècules per a ajustar l'estimulació subministrada en temps real. Per exemple, la segregació de serotonina és una resposta identificada amb l'elongació de les cèl·lules precursores neurals, però hi ha altres biomolècules d'interés per a la implementació d'un control en llaç tancat. Entre les tecnologies en l'estat de l'art, els biosensors basats en transistors d'efecte de camp (FET) funcionalitzats amb aptàmers són realment prometedors per a aquesta aplicació. No obstant això, aquesta tecnologia no permetia el mesurament simultani de més d'una biomolècula objectiu en un volum reduït a causa de les interferències entre els diferents FETs, els terminals dels quals es troben immersos en la solució. Per això, hem desenvolupat instrumentació electrònica capaç de mesurar simultàniament diversos d'aquests biosensors i els hem validat amb mesurament simultani del pH i la detecció preliminar de serotonina i glutamat.[EN] The stem cells' ability to proliferate to form different specialized cells gives them the potential to serve as the basis for effective therapies for pathologies whose treatment was unimaginable until just two decades ago. However, this capacity is mediated by specific and complex physiological, chemical, and electrical stimuli that complicate their translation to clinical routine. For this reason, stem cells represent a field of study in which the scientific community is investing a great deal of effort. In the field of nerve regeneration, to modulate their development and differentiation, pharmacological treatment, electrostimulation, and optogenetic stimulation are techniques that are achieving promising results. For this reason, we have developed a set of electronic systems to allow the combined application of these techniques in vitro, with a view to their application in vivo. We have designed a novel technology for the electrically controlled release of drugs. This technology is based on mesoporous silica nanoparticles and bipyridine-heparin molecular gates. The molecular gates are electrochemically reactive and entrap the drugs inside the nanoparticles, releasing them upon electrical stimulus. We have characterized this technology and validated it by controlled release of rhodamine in HeLa cell cultures. For combining electrostimulation and controlled drug release we have developed devices that allow applying the different electrical stimuli in a configurable way from a graphical user interface. In addition, we have designed an expansion module that allows multiplexing electrical signals to different cell cultures. In addition, we have designed an optogenetic stimulation device. This type of stimulation consists of genetically modifying cells to make them sensitive to light radiation of a specific wavelength. In tissue regeneration using neural precursor cells, it is interesting to be able to induce calcium waves, favoring the cell differentiation into neurons and the formation of synaptic circuits. The designed device enable the obtention of real-time images through confocal microscopy of the transient responses of cells upon irradiation. The device has been validated by irradiating modified neurons with 100 ms pulsed light stimulation. We have also designed a complementary electronic irradiance measurement device to allow calibration of the irradiator equipment and measuring irradiance in real time during in vitro experiments. The results of using bioactuators in complex and dynamic processes, such as nerve tissue regeneration, are limited in an open loop. One of the main aspects analyzed is the development of biosensors that would allow quantifying of specific biomolecules to adjust the stimulation provided in real time. For instance, serotonin secretion is an identified response of neural precursor cells elongation, among other biomolecules of interest for the implementation of a closed-loop control. Among the state-of-the-art technologies, biosensors based on field effect transistors (FETs) functionalized with aptamers are promising for this application. However, this technology did not allow the simultaneous measurement of more than one target biomolecule in a small volume due to interferences between the different FETs, whose terminals are immersed in the solution. This is why we have developed electronic instrumentation capable of simultaneously measuring several of these biosensors, and we have validated it with the simultaneous pH measurement and the preliminary detection of serotonin and glutamate.Monreal Trigo, J. (2023). Electronic Devices for the Combination of Electrically Controlled Drug Release, Electrostimulation, and Optogenetic Stimulation for Nerve Tissue Regeneration [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/19384

    Optimierung alpiner Photovoltaikanlagen

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    In dieser Bachelorarbeit werden drei Optimierungsparameter für alpine Photovoltaikanlagen untersucht, welche den Mehrertrag durch die Nachführung bifazialer Module, den Ertragsverlust der Rückseite bifazialer Module durch die Unterkonstruktion sowie den Einfluss einer Wechselrichter-Abregelung auf die resultierende Verlustleistung umfassen. Ziel dieser Arbeit ist es herauszufinden, wie alpine Photovoltaikanlagen in den genannten Parametern bestmöglich optimiert werden können, sodass ein effizienter Ausbau der solchen gewährleistet werden kann. Dazu wurde in einem ersten Schritt relevante Literatur konsultiert, um die Grundlage für weitere Untersuchungen zu bilden. Anschliessend wurden Konzepte für den Bau von Testanlagen erstellt, deren Messergebnisse dazu dienten, den Mehrertrag gegenüber Referenzsystemen zu quantifizieren. Die erste betrachtete Optimierungsmöglichkeit besteht in der Nachführung bifazialer Module, wodurch der spezifische Ertrag erhöht werden soll. Dazu wurde ursprünglich eine alpine Mini-Testanlage geplant, welche jedoch nicht gebaut wurde, da der zugehörige Algorithmus nicht erstellt werden konnte. Die Planung der alpinen Mini-Testanlage umfasst die Recherche der klimabedingten Anforderungen an die Geräte und Sensoren bis hin zum Elektroschema, wobei als Resultat das Messkonzept sowie der Bau des Schaltschranks gilt. Infolgedessen wurde eine Mini-Testanlage im Kontext der Agri-Photovoltaik geplant und errichtet, wobei ein selbstgebauter, zweiachsiger Tracker und ein eigens geschriebener astronomischer Algorithmus zum Einsatz kam. Die Auswertung der Messungen zeigte, dass durch die zweiachsige Nachführung der bifazialen Module bei hohem Diffusstrahlungsanteil eine Erhöhung der Einstrahlung in die Modulvorderseite von 15 %, in die Modulrückseite von 28 %, und jene in die Modulebenen insgesamt (Vorder- und Rückseite zusammen) von 17 % erreicht wurde. Bei hohem Direktstrahlungsanteil lag die Erhöhung der Einstrahlung in die Modulvorderseite bei 46 %, in die Modulrückseite bei 19 % und insgesamt bei 42 %. Durch die Modulrückseite (Bifazialitätsfaktor = 100 %) konnte die Einstrahlung in die Modulebene um 21 % bei hohem Diffus-, und um 15 % bei hohem Direktstrahlungsanteil gesteigert werden. Als zweite Optimierung wurde der Ertragsverlust durch die Unterkonstruktion auf der Rückseite bifazialer Module untersucht, wobei es herauszufinden galt, wie dieser bestmöglich reduziert werden kann. Dazu wurde ebenfalls eine Testanlage errichtet, und die Modulleistungen bei insgesamt sechs Szenarien mit unterschiedlicher Anordnung und Anzahl der Querstreben gemessen. Dabei stellte sich heraus, dass der Ertragsverlust bei gleichbleibender Anzahl an Querstreben reduziert werden kann, wenn diese mit einem Abstand zum Modul von 5 cm montiert werden, anstatt ohne Abstand zu diesem, wobei der Ertragsverlust durch den Abstand um bis zu 59 % reduziert werden kann. Zuletzt wurde der Einfluss einer Wechselrichter-Abregelung bei 60 und 90° geneigten, bifazialen Modulen betrachtet, für dessen Untersuchung Messdaten der bestehenden ZHAW-Testanlage auf der Totalp zur Verfügung gestellt wurden. Dabei galt es herauszufinden, welchen Einfluss verschiedene Begrenzungsstufen auf die resultierende Verlustleistung haben, und in welcher zeitlichen Auflösung Produktionsprofile von Photovoltaikanlagen vorliegen müssen, um Fragestellungen rund um die Abregelung beantworten zu können. Die Auswertung der Daten zeigte, dass bei 60° geneigten Modulen von höheren Verlustleistungen je Begrenzungsstufe ausgegangen werden muss, im Vergleich zu denen bei 90° geneigten. Die höchsten relativen Verlustleistungen werden bei beiden betrachteten Modulsegmenten in den Wintermonaten November bis März erreicht, oder bei tageszeitlicher Betrachtung über die Mittagsstunden von 10 bis 14 Uhr. Beispielsweise resultiert bei einer Abregelung auf 80 % der Nennleistung bei den 60° geneigten Modulen ein jährlicher Ertragsverlust von 14 % und bei den 90 ° Geneigten einer von 17 %, wobei die Verluste in den Wintermonaten höher sind als im Sommer.This bachelor's thesis examines three optimization parameters for alpine photovoltaic systems, which include the additional yield through the tracking of bifacial modules, the rear-side yield loss of bifacial modules due to the substructure, and the impact of inverter curtailment on resulting energy losses. The aim of this thesis is to determine how alpine photovoltaic systems can be optimized most effectively in these parameters to ensure efficient expansion. To achieve this, relevant literature was consulted in the initial step to provide a foundation for further investigations. Subsequently, concepts for the construction of test systems were developed, and their measurement results were used to quantify the additional yield compared to reference systems. The first optimization possibility examined is the tracking of bifacial modules to increase specific yield. Initially, an alpine mini-test system was planned for this purpose, but it was not built due to the inability to create the associated algorithm. The planning of the alpine mini-test system involved researching the climatic requirements for the devices and sensors and developing the electrical schematic. The result of this planning was the measurement concept and the construction of the control cabinet. As a result, a mini-test system was planned and constructed in the context of Agri-photovoltaics, utilizing a self-built dual-axis tracker and a custom-written astronomical algorithm. The evaluation of the measurements showed that the two-axis tracking of bifacial modules achieved an increase in irradiation on the front side of the modules by 15 % and on the rear side by 28 % under high diffuse radiation conditions. Overall, the irradiation on both sides (front and rear) of the modules increased by 17 %. Under high direct radiation conditions, the increase in irradiation on the front side was 46 %, on the rear side was 19 %, and overall was 42 %. By utilizing the rear side of the modules (bifaciality factor = 100 %), the irradiation on the module plane increased by 21 % under high diffuse radiation and by 15 % under high direct radiation. The second optimization examined was the yield loss caused by the substructure on the rear side of bifacial modules. The goal was to determine how this loss could be reduced most effectively. For this purpose, another test system was built, and the module performance was measured under six scenarios with different arrangements and numbers of crossbars. It was found that, with a consistent number of crossbars, the yield loss could be reduced by mounting them with a 5 cm spacing from the module compared to mounting them without any spacing. The yield loss could be reduced by up to 59 % due to the spacing. Lastly, the influence of inverter curtailment on 60° and 90° tilted bifacial modules was examined. For this investigation, measurement data from the existing ZHAW test system at Totalp was made available. The aim was to determine the impact of different curtailment levels on resulting power losses and to identify the temporal resolution required for production profiles of photovoltaic systems to address curtailment-related questions. The data evaluation showed that higher power losses per curtailment level should be expected for the 60° tilted modules compared to the 90° tilted modules. The highest relative power losses for both module segments occurred during the winter months from November to March, or when considering the midday hours from 10 am to 2 pm. For example, a curtailment to 80 % of the rated power resulted in an annual yield loss of 14 % for the 60° tilted modules and 17 % for the 90° tilted modules, with losses being higher in the winter months than in the summer

    Jornadas Nacionales de Investigación en Ciberseguridad: actas de las VIII Jornadas Nacionales de Investigación en ciberseguridad: Vigo, 21 a 23 de junio de 2023

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    Jornadas Nacionales de Investigación en Ciberseguridad (8ª. 2023. Vigo)atlanTTicAMTEGA: Axencia para a modernización tecnolóxica de GaliciaINCIBE: Instituto Nacional de Cibersegurida

    MOCAST 2021

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    The 10th International Conference on Modern Circuit and System Technologies on Electronics and Communications (MOCAST 2021) will take place in Thessaloniki, Greece, from July 5th to July 7th, 2021. The MOCAST technical program includes all aspects of circuit and system technologies, from modeling to design, verification, implementation, and application. This Special Issue presents extended versions of top-ranking papers in the conference. The topics of MOCAST include:Analog/RF and mixed signal circuits;Digital circuits and systems design;Nonlinear circuits and systems;Device and circuit modeling;High-performance embedded systems;Systems and applications;Sensors and systems;Machine learning and AI applications;Communication; Network systems;Power management;Imagers, MEMS, medical, and displays;Radiation front ends (nuclear and space application);Education in circuits, systems, and communications
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