EPIC - Energy Processing and Integrated Circuits
http://hdl.handle.net/2117/3239
2024-03-29T13:27:02Z
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Heterogeneous degradation in Li-ion batteries
http://hdl.handle.net/2117/405178
Heterogeneous degradation in Li-ion batteries
Ovejas Benedicto, Victòria Júlia; Cuadras Tomàs, Àngel
Li-ion batteries are crucial for the forthcoming energy transition. They are complex systems that show heterogeneous current distribution patterns and degradation. The development of valid methods to determine their internal state as well as for performance optimization and life cycle extension are vital for battery full deployment.We study the entropy production in the cells in the presence of temperature gradients.We observe that entropy is produced faster in the regions with larger temperatures which are generally associated with faster degradation patterns.
2024-03-22T13:22:56Z
Ovejas Benedicto, Victòria Júlia
Cuadras Tomàs, Àngel
Li-ion batteries are crucial for the forthcoming energy transition. They are complex systems that show heterogeneous current distribution patterns and degradation. The development of valid methods to determine their internal state as well as for performance optimization and life cycle extension are vital for battery full deployment.We study the entropy production in the cells in the presence of temperature gradients.We observe that entropy is produced faster in the regions with larger temperatures which are generally associated with faster degradation patterns.
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MATLAB® modeling of a microgrid: towards a vision based on entropy balance
http://hdl.handle.net/2117/404380
MATLAB® modeling of a microgrid: towards a vision based on entropy balance
Khan, Ameer Abdullah; Martínez García, Herminio; Cuadras Tomàs, Àngel
A microgrid is defined as the link of consumer loads and decentralized energy assets with the ability to control the entire system as a whole. The modeling of an electromagnetic microgrid is discussed in this work to analyze energy effectiveness and entropy balance. The method computes the associated losses and simulates the electrical behavior of the components. The model is built and tested by using the MATLAB Simulink application. The system is made up of several blocks consisting of solar panels, batteries, consumer loads, and the inverter needed to connect them all. Their energy efficiency is assessed using the findings from each of these components. The system's entropy generation is also calculated to study how it relates to performance.
2024-03-13T09:21:51Z
Khan, Ameer Abdullah
Martínez García, Herminio
Cuadras Tomàs, Àngel
A microgrid is defined as the link of consumer loads and decentralized energy assets with the ability to control the entire system as a whole. The modeling of an electromagnetic microgrid is discussed in this work to analyze energy effectiveness and entropy balance. The method computes the associated losses and simulates the electrical behavior of the components. The model is built and tested by using the MATLAB Simulink application. The system is made up of several blocks consisting of solar panels, batteries, consumer loads, and the inverter needed to connect them all. Their energy efficiency is assessed using the findings from each of these components. The system's entropy generation is also calculated to study how it relates to performance.
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A secure dual-layer fault protection strategy for distribution network with DERs: enhancing security in the face of communication challenges
http://hdl.handle.net/2117/404203
A secure dual-layer fault protection strategy for distribution network with DERs: enhancing security in the face of communication challenges
Al Hanaineh, Wael Hasan Ahmad; Matas Alcalá, José; Guerrero Zapata, Josep Maria; Bakkar, Mostafa
Earlier protection methods mainly focused on using communication channels to transmit trip signals between the protective devices (PDs), with no solutions provided in the case of communication failure. Therefore, this paper introduces a dual-layer protection system to ensure secure protection against fault events in the Distribution Systems (DSs), particularly in light of communication failures. The initial layer uses the Total Harmonic Distortion (THD), the estimates of the amplitude voltages, and the zero-sequence grid voltage components, functioning as a fault sensor, to formulate an adaptive algorithm based on a Finite State Machine (FSM) for the detection and isolation of faults within the grid. This layer primarily relies on communication protocols for effective coordination. A Second-Order Generalized Integrator (SOGI) expedites the derivation of the estimated variables, ensuring fast detection with minimal computational overhead. The second layer uses the behavior of the positive- and negative-sequence components of the grid voltages during fault events to locate and isolate these faults. In the event that the first layer exposes a communication failure, the second layer will automatically be activated to ensure secure protection as it operates, using the local information of the Protective devices (PDs), without the need for communication channels to transmit trip signals between the PDs. The proposed protection system has been assessed using simulations with MATLAB/Simulink and providing experimental results considering an IEEE 9-bus standard radial system. The obtained results confirm the capability of the system for identifying and isolating different types of faults, varying conditions, and modifications to the grid configuration. The results show good behavior of the initial THD-based layer, with fast time responses ranging from 6 to 8.5 ms in all the examined scenarios. In contrast, the sequence-based layer exhibits a protection time response of approximately 150 ms, making it a viable backup option in the event of a communication failure.
2024-03-12T12:55:23Z
Al Hanaineh, Wael Hasan Ahmad
Matas Alcalá, José
Guerrero Zapata, Josep Maria
Bakkar, Mostafa
Earlier protection methods mainly focused on using communication channels to transmit trip signals between the protective devices (PDs), with no solutions provided in the case of communication failure. Therefore, this paper introduces a dual-layer protection system to ensure secure protection against fault events in the Distribution Systems (DSs), particularly in light of communication failures. The initial layer uses the Total Harmonic Distortion (THD), the estimates of the amplitude voltages, and the zero-sequence grid voltage components, functioning as a fault sensor, to formulate an adaptive algorithm based on a Finite State Machine (FSM) for the detection and isolation of faults within the grid. This layer primarily relies on communication protocols for effective coordination. A Second-Order Generalized Integrator (SOGI) expedites the derivation of the estimated variables, ensuring fast detection with minimal computational overhead. The second layer uses the behavior of the positive- and negative-sequence components of the grid voltages during fault events to locate and isolate these faults. In the event that the first layer exposes a communication failure, the second layer will automatically be activated to ensure secure protection as it operates, using the local information of the Protective devices (PDs), without the need for communication channels to transmit trip signals between the PDs. The proposed protection system has been assessed using simulations with MATLAB/Simulink and providing experimental results considering an IEEE 9-bus standard radial system. The obtained results confirm the capability of the system for identifying and isolating different types of faults, varying conditions, and modifications to the grid configuration. The results show good behavior of the initial THD-based layer, with fast time responses ranging from 6 to 8.5 ms in all the examined scenarios. In contrast, the sequence-based layer exhibits a protection time response of approximately 150 ms, making it a viable backup option in the event of a communication failure.
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Procedure for component sizing in off-grid networked microgrids
http://hdl.handle.net/2117/403936
Procedure for component sizing in off-grid networked microgrids
Salehi, Navid; Martínez García, Herminio; Velasco Quesada, Guillermo
Stand-alone Microgrids (MGs) can effectively be utilized to provide the energy demand for different purposes, such as reducing the burden of the main grid. Paying attention to harvesting renewable energies in MGs resulted in coming up with networked MG (NMG) in recent years. Unlike individual MGs, there is no prominent study on component sizing in NMG. In this paper, a novel component sizing procedure is proposed for NMG. The proposed procedure is based on the optimal operation of each individual MGs. The proposed reduced factor (RF) determines the size reduction of each component in NMG. In order to validate the proposed method, the NMG's operation is evaluated according to the calculated component's size. The results show, in NMG, the capital cost can reduce significantly due to the possibility of power-sharing amongst MGs.
2024-03-07T14:13:19Z
Salehi, Navid
Martínez García, Herminio
Velasco Quesada, Guillermo
Stand-alone Microgrids (MGs) can effectively be utilized to provide the energy demand for different purposes, such as reducing the burden of the main grid. Paying attention to harvesting renewable energies in MGs resulted in coming up with networked MG (NMG) in recent years. Unlike individual MGs, there is no prominent study on component sizing in NMG. In this paper, a novel component sizing procedure is proposed for NMG. The proposed procedure is based on the optimal operation of each individual MGs. The proposed reduced factor (RF) determines the size reduction of each component in NMG. In order to validate the proposed method, the NMG's operation is evaluated according to the calculated component's size. The results show, in NMG, the capital cost can reduce significantly due to the possibility of power-sharing amongst MGs.
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Estrategias de gestión de microrredes eléctricas colaborativas para prosumidores domésticos
http://hdl.handle.net/2117/403927
Estrategias de gestión de microrredes eléctricas colaborativas para prosumidores domésticos
Lomascolo Pujadó, Agnès; Martínez García, Herminio
El presente trabajo tiene como objetivo el análisis de diferentes escenarios con microrredes domésticas con colaboración entre prosumidores domésticos. Se persigue encontrar estrategias que permiten una optimización de la colaboración entre los prosumidores que conforman los casos estudiados considerados en el artículo. El sistema de gestión de energía diseñado distribuye los flujos energéticos teniendo en cuenta una serie de parámetros y siguiendo una colaboración entre pares o peer-to-peer (P2P), específicamente el método store-then-cooperate (STC).
2024-03-07T13:21:17Z
Lomascolo Pujadó, Agnès
Martínez García, Herminio
El presente trabajo tiene como objetivo el análisis de diferentes escenarios con microrredes domésticas con colaboración entre prosumidores domésticos. Se persigue encontrar estrategias que permiten una optimización de la colaboración entre los prosumidores que conforman los casos estudiados considerados en el artículo. El sistema de gestión de energía diseñado distribuye los flujos energéticos teniendo en cuenta una serie de parámetros y siguiendo una colaboración entre pares o peer-to-peer (P2P), específicamente el método store-then-cooperate (STC).
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Simple fuzzy logic-based energy management for power exchange in isolated multi-microgrid systems: a case study in a remote community in the Amazon region of Ecuador
http://hdl.handle.net/2117/403845
Simple fuzzy logic-based energy management for power exchange in isolated multi-microgrid systems: a case study in a remote community in the Amazon region of Ecuador
Rodríguez, Mauricio; Arcos Aviles, Diego Gustavo; Guinjoan Gispert, Francisco
Nowadays, the increase in electric power coverage worldwide is a priority scope of the study, where Microgrids (MG) emerge as feasible solutions to supply electricity. The use of MG to provide energy to isolated communities, especially its use as Isolated Multi-Microgrid (IMMG) systems, has become an object of study worldwide. Different control techniques have been developed to improve and optimize the energy management system (EMS) associated with an isolated MG and new alternatives for energy exchange between IMMGs. However, the geographical location of a possible implementation of an MG directly affects the optimal dimensioning, the operating cost, and the environmental impact, among others. In this context, this work proposes a novel design of an EMS based on a fuzzy logic controller focusing on power exchange between IMMG systems. The proposed EMS aims to minimize the consumption of fossil fuels, reduce the total energy wasted by the power generation units, and keep the state-of-charge of the energy storage system (ESS) at safe levels to extend its useful life. Moreover, an ESS state of health analysis is presented to determine its degradation over time when applying the proposed EMS. In addition, the proposed EMS considers the uncertainties in the disconnection of any MG, ensuring the independent operation of each one. Simulation results are performed for a case study of an isolated community in the Amazon region of Ecuador. For this purpose, a group of microgrids is considered in three different scenarios. In the first scenario, there is no power exchange between the microgrids. In the second scenario, the microgrids exchange power using a simple EMS based on a set of analytical rules, and in the third scenario, the microgrids exchange power using the proposed EMS. The results show an improvement in the overall performance of the third scenario compared to the first two, both in reducing the energy wasted by the PV system and in the cost of fossil fuel. Finally, the experimental validation, using Typhoon Hardware-in-the-loop HIL-402 devices in real-time operation, highlights the proposed EMS's effectiveness and feasibility for IMMG systems.
© 2024 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
2024-03-06T12:03:40Z
Rodríguez, Mauricio
Arcos Aviles, Diego Gustavo
Guinjoan Gispert, Francisco
Nowadays, the increase in electric power coverage worldwide is a priority scope of the study, where Microgrids (MG) emerge as feasible solutions to supply electricity. The use of MG to provide energy to isolated communities, especially its use as Isolated Multi-Microgrid (IMMG) systems, has become an object of study worldwide. Different control techniques have been developed to improve and optimize the energy management system (EMS) associated with an isolated MG and new alternatives for energy exchange between IMMGs. However, the geographical location of a possible implementation of an MG directly affects the optimal dimensioning, the operating cost, and the environmental impact, among others. In this context, this work proposes a novel design of an EMS based on a fuzzy logic controller focusing on power exchange between IMMG systems. The proposed EMS aims to minimize the consumption of fossil fuels, reduce the total energy wasted by the power generation units, and keep the state-of-charge of the energy storage system (ESS) at safe levels to extend its useful life. Moreover, an ESS state of health analysis is presented to determine its degradation over time when applying the proposed EMS. In addition, the proposed EMS considers the uncertainties in the disconnection of any MG, ensuring the independent operation of each one. Simulation results are performed for a case study of an isolated community in the Amazon region of Ecuador. For this purpose, a group of microgrids is considered in three different scenarios. In the first scenario, there is no power exchange between the microgrids. In the second scenario, the microgrids exchange power using a simple EMS based on a set of analytical rules, and in the third scenario, the microgrids exchange power using the proposed EMS. The results show an improvement in the overall performance of the third scenario compared to the first two, both in reducing the energy wasted by the PV system and in the cost of fossil fuel. Finally, the experimental validation, using Typhoon Hardware-in-the-loop HIL-402 devices in real-time operation, highlights the proposed EMS's effectiveness and feasibility for IMMG systems.
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Wearable device para la prevención de accidentes en personas con sonambulismo
http://hdl.handle.net/2117/403473
Wearable device para la prevención de accidentes en personas con sonambulismo
Deltor Cortés, Eva María; Martínez García, Herminio
El sonambulismo es un trastorno del sueño que afecta principalmente a niños y adolescentes; sin embargo, se considera que aproximadamente el 2 % de la población adulta lo padece. Se desconocen las causas de su aparición; no obstante, las consecuencias resultantes pueden ser peligrosas puesto que el individuo puede realizar acciones como caminar, ducharse o salir de casa, mientras duerme; por lo tanto, de manera inconsciente. Este artículo no sólo presenta un sistema cuyo objetivo es evitar aquellas situaciones inseguras para el sonámbulo, sino que se distingue de los métodos empleados actualmente en donde se detectan este tipo de eventos empleando cámaras y sensores de movimiento, sino que procura ir un paso más allá; evitar que la persona se levante de la cama mediante señales electroencefalográficas que permiten detectar el sonambulismo des de su inicio, siendo capaces de pararlo usando una pulsera vibratoria.
2024-02-29T14:18:01Z
Deltor Cortés, Eva María
Martínez García, Herminio
El sonambulismo es un trastorno del sueño que afecta principalmente a niños y adolescentes; sin embargo, se considera que aproximadamente el 2 % de la población adulta lo padece. Se desconocen las causas de su aparición; no obstante, las consecuencias resultantes pueden ser peligrosas puesto que el individuo puede realizar acciones como caminar, ducharse o salir de casa, mientras duerme; por lo tanto, de manera inconsciente. Este artículo no sólo presenta un sistema cuyo objetivo es evitar aquellas situaciones inseguras para el sonámbulo, sino que se distingue de los métodos empleados actualmente en donde se detectan este tipo de eventos empleando cámaras y sensores de movimiento, sino que procura ir un paso más allá; evitar que la persona se levante de la cama mediante señales electroencefalográficas que permiten detectar el sonambulismo des de su inicio, siendo capaces de pararlo usando una pulsera vibratoria.
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Guided activities in the teaching of analogue electronics in the bachelor’s degree in industrial and automatic electronics
http://hdl.handle.net/2117/403472
Guided activities in the teaching of analogue electronics in the bachelor’s degree in industrial and automatic electronics
Martínez García, Herminio
Within the offer of core courses of the Bachelor’s Degree in Industrial Electronics and Automation Engineering of the Technical University of Catalonia (UPC), which appeared as a result of the current undergraduate study program, within the European Higher Education Area (EHEA), there is a course, Analog Electronics (EAEIA), which allows the Electronic Engineering student to delve into the knowledge of this content. This paper exposes the philosophy of this course, in such a way that it analyzes the orientation that is intended to be given, especially within the new framework of courses offered at the EEBE where, in addition to the hours of lectures and laboratory sessions, there must be room for to the guided activities (GAs) that the current syllabus contemplates.
2024-02-29T14:12:26Z
Martínez García, Herminio
Within the offer of core courses of the Bachelor’s Degree in Industrial Electronics and Automation Engineering of the Technical University of Catalonia (UPC), which appeared as a result of the current undergraduate study program, within the European Higher Education Area (EHEA), there is a course, Analog Electronics (EAEIA), which allows the Electronic Engineering student to delve into the knowledge of this content. This paper exposes the philosophy of this course, in such a way that it analyzes the orientation that is intended to be given, especially within the new framework of courses offered at the EEBE where, in addition to the hours of lectures and laboratory sessions, there must be room for to the guided activities (GAs) that the current syllabus contemplates.
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A contribution to students’ assessment adjusts of multiple choice questionnaires with fuzzy logic
http://hdl.handle.net/2117/403470
A contribution to students’ assessment adjusts of multiple choice questionnaires with fuzzy logic
Domingo Peña, Joan; Martínez García, Herminio
In University environment, it is common to use multiple-choice objective tests with three or four possible answers, of which only one is correct and the rest are erroneous. In this type of tests, usually the wrong answers are penalized in order to avoid the effect of the random answers. However, there are questions that hardly students answer since their difficulty is high. On the other hand, there are also questions that answer virtually all students since their difficulty is simple. While sometimes the course professor chooses to suppress these questions, it is also common to leave them as part of the calculation of the overall score. This communication proposes a way of, without suppressing any question, making a readjustment of the grades based on fuzzy logic techniques. To do this, it is considered, on the one hand, the initial grade obtained by each student and, on the other, the total difficulty index of the test. With these two variables, an approximation can be made to a system of linguistic variables that allows correcting the final grades of each student based on the objective difficulty of the test and a set of rules established by the professor. This will revert to greater “justice” in students’ mark system, since it will be a function of the difficulty of the test.
2024-02-29T14:09:35Z
Domingo Peña, Joan
Martínez García, Herminio
In University environment, it is common to use multiple-choice objective tests with three or four possible answers, of which only one is correct and the rest are erroneous. In this type of tests, usually the wrong answers are penalized in order to avoid the effect of the random answers. However, there are questions that hardly students answer since their difficulty is high. On the other hand, there are also questions that answer virtually all students since their difficulty is simple. While sometimes the course professor chooses to suppress these questions, it is also common to leave them as part of the calculation of the overall score. This communication proposes a way of, without suppressing any question, making a readjustment of the grades based on fuzzy logic techniques. To do this, it is considered, on the one hand, the initial grade obtained by each student and, on the other, the total difficulty index of the test. With these two variables, an approximation can be made to a system of linguistic variables that allows correcting the final grades of each student based on the objective difficulty of the test and a set of rules established by the professor. This will revert to greater “justice” in students’ mark system, since it will be a function of the difficulty of the test.
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Assessment based on fuzzy logic of multiple choice questionnaires
http://hdl.handle.net/2117/403469
Assessment based on fuzzy logic of multiple choice questionnaires
Domingo Peña, Joan; Martínez García, Herminio
In University environment, it is common to use multiple-choice objective tests with three or four possible answers, of which only one is correct and the rest are erroneous. In this type of tests, usually the wrong answers are penalized in order to avoid the effect of the random answers. However, there are questions that hardly students answer since their difficulty is high. On the other hand, there are also questions that answer virtually all students since their difficulty is simple. While sometimes the course professor chooses to suppress these questions, it is also common to leave them as part of the calculation of the overall score. This communication proposes a way of, without suppressing any question, making a readjustment of the grades based on fuzzy logic techniques. To do this, it is considered, on the one hand, the initial grade obtained by each student and, on the other, the total difficulty index of the test. With these two variables, an approximation can be made to a system of linguistic variables that allows correcting the final grades of each student based on the objective difficulty of the test and a set of rules established by the professor. This will revert to greater “justice” in students’ mark system, since it will be a function of the difficulty of the test.
2024-02-29T14:05:24Z
Domingo Peña, Joan
Martínez García, Herminio
In University environment, it is common to use multiple-choice objective tests with three or four possible answers, of which only one is correct and the rest are erroneous. In this type of tests, usually the wrong answers are penalized in order to avoid the effect of the random answers. However, there are questions that hardly students answer since their difficulty is high. On the other hand, there are also questions that answer virtually all students since their difficulty is simple. While sometimes the course professor chooses to suppress these questions, it is also common to leave them as part of the calculation of the overall score. This communication proposes a way of, without suppressing any question, making a readjustment of the grades based on fuzzy logic techniques. To do this, it is considered, on the one hand, the initial grade obtained by each student and, on the other, the total difficulty index of the test. With these two variables, an approximation can be made to a system of linguistic variables that allows correcting the final grades of each student based on the objective difficulty of the test and a set of rules established by the professor. This will revert to greater “justice” in students’ mark system, since it will be a function of the difficulty of the test.