Modular PEM Fuel Cell SCADA & Simulator System

The paper presents a Supervision, Control, Data Acquisition and Simulation (SCADA & Simulator) system that allows for real-time training in the actual operation of a modular PEM fuel cell system. This SCADA & Simulator system consists of a free software tool that operates in real time and simulates real situations like failures and breakdowns in the system. This developed SCADA & Simulator system allows us to properly operate a fuel cell and helps us to understand how fuel cells operate and what devices are needed to configure and run the fuel cells, from the individual stack up to the whole fuel cell system. The SCADA & Simulator system governs a modular system integrated by three PEM fuel cells achieving power rates higher than tens of kilowatts

Olive-Fruit Variety Classification by Means of Image Processing and Convolutional Neural Networks

The automation of classifcation and grading of horticultural products attending to different features comprises a major challenge in food industry. Thus, focused on the olive sector, which boasts of a huge range of cultivars, it is proposed a methodology for olive-fruit variety classifcation, approaching it as an image classifcation problem. To that purpose, 2,800 fruits belonging to seven different olive varieties were photographed. After processing these initial captures by means of image processing techniques, the resulting set of images of individual fruits were used to train, and continuedly to externally validate, the implementations of six different Convolutional Neural Networks architectures. This, in order to compute the classifers with which perform the variety categorization of the fruits. Remarkable hit rates were obtained after testing the classifers on the corresponding external validation sets. Thus, it was yielded a top accuracy of 95.91% when using the Inception-ResnetV2 architecture. The results suggest that the proposed methodology, once integrated into industrial conveyor belts, promises to be an advanced solution to postharvest olive-fruit processing and classifcation

Green Hydrogen: Resources Consumption, Technological Maturity, and Regulatory Framework

Current climate crisis makes the need for reducing carbon emissions more than evident. For this reason, renewable energy sources are expected to play a fundamental role. However, these sources are not controllable, but depend on the weather conditions. Therefore, green hydrogen (hydrogen produced from water electrolysis using renewable energies) is emerging as the key energy carrier to solve this problem. Although different properties of hydrogen have been widely studied, some key aspects such as the water and energy footprint, as well as the technological development and the regulatory framework of green hydrogen in different parts of the world have not been analysed in depth. This work performs a data-driven analysis of these three pillars: water and energy footprint, technological maturity, and regulatory framework of green hydrogen technology. Results will allow the evaluation of green hydrogen deployment, both the current situation and expectations. Regarding the water footprint, this is lower than that of other fossil fuels and competitive with other types of hydrogen, while the energy footprint is higher than that of other fuels. Additionally, results show that technological and regulatory framework for hydrogen is not fully developed and there is a great inequality in green hydrogen legislation in different regions of the world.This research was funded by the Spanish Government, grant (1) Ref: PID2020-116616RBC31, and grant (2) Ref: RED2022-134588-T REDGENERA

Generalized, Complete and Accurate Modeling of Non-Ideal Push–Pull Converters for Power System Analysis and Control

Power converters are a basic element for the control and design of any power electronic system. Among the many available topologies, the push–pull converter is widely used due to its versatility, safety and efficiency. For its correct analysis, sizing, simulation and control, models that meet the characteristics of generality, accuracy and simplicity are required, especially if its control is to be optimized by means of some analytical technique. This requires models that consider the practical non-idealities intrinsic to the converter, as well as being intuitive and easy to handle analytically in a control loop. In general, the models reviewed in the scientific literature adopt simplifications in their definition that are detrimental to their accuracy. In response to the posed problem, this work presents a generalized, complete, accurate and versatile model of real (non-ideal) push–pull converters, ideal for the analysis, simulation, and control of power systems. Following the premise of general and complete converters, the proposed model includes all the practical non-idealities of the converter elements, and it is accurate because it faithfully reflects its dynamics. Furthermore, the model is versatile, as its state space formulation allows for its easy adaptability to the converter operating conditions (voltage, current and temperature) for each sampling time. Also, the model is excellent for use in model-based control techniques, as well as for making very accurate simulators. The behavior of the developed model has been contrasted with a real push–pull converter, as well as with reference models present in the scientific literature for both dynamic and steady-state response tests. The results show excellent performance in all the studied cases, with behavior faithful to the real converter and with relative errors that are much lower than those obtained for the reference models. It follows that the model behaves like a digital twin of a real push–pull converter.This work is a contribution of the two following projects: “H2Integration&Control. Integration and Control of a hydrogen-based pilot plant in residential applications for energy supply”, Ref. PID2020-116616RB-C31 supported by the Spanish State Program of R+D+I Oriented to the Challenges of Society; and “SALTES: Smartgrid with reconfigurable Architecture for testing controL Techniques and Energy Storage priority contaminant waste”, Ref. P20-00730 supported by Andalusian Regional Program of R+D+I

Fuzzy logic-based energy management system for grid-connected residential DC microgrids with multi-stack fuel cell systems: A multi-objective approach

Hybrid energy storage systems (HESS) are considered for use in renewable residential DC microgrids. This architecture is shown as a technically feasible solution to deal with the stochasticity of renewable energy sources, however, the complexity of its design and management increases inexorably. To address this problem, this paper proposes a fuzzy logic-based energy management system (EMS) for use in grid-connected residential DC microgrids with HESS. It is a hydrogen-based HESS, composed of batteries and multi-stack fuel cell system. The proposed EMS is based on a multivariable and multistage fuzzy logic controller, specially designed to cope with a multi-objective problem whose solution increases the microgrid performance in terms of efficiency, operating costs, and lifespan of the HESS. The proposed EMS considers the power balance in the microgrid and its prediction, the performance and degradation of its subsystems, as well as the main electricity grid costs. This article assesses the performance of the developed EMS with respect to three reference EMSs present in the literature: the widely used dual-band hysteresis and two based on multi-objective model predictive control. Simulation results show an increase in the performance of the microgrid from a technical and economic point of view.Thisresearchwasfundedby‘‘H2Integration&Control.IntegrationandControlofahydrogen-basedpilotplantinresidentialapplicationsforenergysupply’’SpanishGovernment,grant Ref:PID2020-116616RB-C31’’,‘‘SALTES:SmartgridwithreconfigurableArchitecturefortestingcontroLTechniquesandEnergy Storagepriority’’byAndalusianRegionalProgramofR+D+i,grant Ref:P20-00730,andbytheproject‘‘Thegreenhydrogenvector. Residentialandmobilityapplication’’,approvedinthecallfor researchprojectsoftheCepsaFoundationChairoftheUniversity ofHuelva.Fundingforopenaccesscharge:UniversidaddeHuelva /CBUA

The Challenge of Digital Transition in Engineering. A Solution Made from a European Collaborative Network of Remote Laboratories Based on Renewable Energies Technology

Society currently faces two crucial challenges: digital transition and energy transition. Educative innovation plays a key role in this challenging scenario, particularly engineering careers, where laboratory practices are as important as theoretical classes. This paper presents a standardized training platform supported by five European universities which include a remote laboratory experience. Each university is responsible for developing a training module under the guidance provided by the responsible entity (University of Huelva, Spain). For this purpose, the University of Huelva has implemented a remote laboratory based on a supercapacitor power bank. The rest of the universities have selected any other renewable source and have replicated the information and communications technology (ICT) infrastructure. The result is a European network materialized on a homogenized platform where teachers and students can find all the teaching materials (theory and practice) to train and to be trained in renewable energy matters in the new digital era.This research was funded by Erasmus+ Programme, grant number Ref. 2020-1-IT02-KA226-HE-095424 RE-OPEN project; ERASMUS+ Programme 2020-KA2; and the APC was funded by Ref. 2020-1-IT02-KA226-HE-095424 RE-OPEN project, founded by ERASMUS+ Programme 2020-KA2

Temperature Measurement in PV Facilities on a Per-Panel Scale

This work is a contribution of the DPI2010-17123 Project supported by the Spanish Ministry of Education and Science and the TEP-6124 Project supported by the Regional Government of Andalusia (Spain). Both projects are also supported by the European Union Regional Development Fund.This paper presents the design, construction and testing of an instrumentation system for temperature measurement in PV facilities on a per-panel scale (i.e., one or more temperature measurements per panel). Its main characteristics are: precision, ease of connection, immunity to noise, remote operation, easy scaling; and all of this at a very low cost. The paper discusses the advantages of temperature measurements in PV facilities on a per-panel scale. The paper presents the whole development to implementation of a real system that is being tested in an actual facility. This has enabled the authors to provide the readers with practical guidelines, which would be very difficult to achieve if the developments were implemented by just simulation or in a theoretical way. The instrumentation system is fully developed, from the temperature sensing to its presentation in a virtual instrument. The developed instrumentation system is able to work both locally and remotely connected to both wired and wireless network

Assessment of aerial thermography as a method of in situ measurement of radiant heat transfer in urban public spaces

Una propuesta de nuevas estrategias para la mejora del medio ambiente urbano, usando termografía aérea para el cálculo de la temperatura media radianteUrban public spaces are an essential part of the urban environment, supporting social relationships and pro- moting a healthy lifestyle among citizens. However, the high value of urban land has led to an over-urbanisation of cities, increasing urban heat stress and decreasing the number and size of public spaces. Rising air temper- atures in cities – known as the urban heat island effect (UHI) - combined with global warming, make public spaces less comfortable. For these reasons, there has been a growing concern to improve the thermal comfort of urban spaces. Thermal radiation is a determining factor in urban thermal comfort and is normally summarised in a value called mean radiant temperature (TMRT). In the past, conventional methods have been used to calculate it, such as net radiometers and globe thermometers. In recent years, the scientific community has used ground- based handheld thermal cameras for its quantification. However, there is a lack of literature on the use of aerial thermography for this purpose (i.e. an unmanned aerial vehicle (UAV) equipped with a thermal infrared device). Given this gap in the literature and the advantages in time, versatility and accuracy of these systems, this paper presents a new method for assessing the measurement of radiant heat transfer in a pedestrian urban space using aerial thermography. From the surface temperatures of the infrared imagery collected by the UAV, TMRT was estimated at multiple points in a pedestrian area of a subtropical city (Huelva, Spain) during a typical summer day. In order to verify accuracy of the proposed method to estimate the TMRT, a microclimate urban simulation was carried out using ENVI-met v5. The comparative analysis of the measured and simulated dataset verified the applicability of aerial thermography for the measurement of radiant heat transfer (with R2 values of 0.98 for the data set and 0.8 for the data of each time period). To conclude, new strategies were proposed to improve urban thermal comfort and to make cities more sustainable.Funding for open access charge: Universidad de Huelva/CBUA. Proyecto SALTES (P20_00730): Smartgrid with reconfigurable Architecture for testing controL Techniques and Energy Storage priority. Programa Operativo FEDER 2014-2020 Junta de Andalucia

The Remote Access to Laboratories: a Fully Open Integrated System

An existing lab experience can be made remotely accessible in a relatively easy way. The problem is with the design of a tool which allows any kind of experience to be made remotely accessible. The complexity of this tool is out of discussion. Several universities have been working on it for years. In fact, the Huelva University presented the work “A Complete Solution for Developing Remote Labs†in the 10th IFAC Symposium on Advances in Control Education (2013). Such complete solution was the result of those universities working together. Since then, the joint-work has continued and improvements have also been achieved. Hereafter, a fully open integrated system is presented whose scope is greater than that of 2013. It offers a way to easily implement cloud services for managing the configuration and access to all type of sensors, actuators and controllers (the devices base of the any remote lab). The access proposed is secure, controlled, organized and collaborativ

Testing Bench for Remote Practical Training in Electric Machines

Remote labs are emerging as a necessary tool to support practical classes in engineering studies. It is due to the increasing number of students who combine their studies with work. In fact, there are numerous developments in areas such as electronics and automatic. However, there are only a few of them in the area of electrical machines. This paper presents a testing bench for remote practical training in electric machines. The security challenges presented by these experiments are overcome by software within the remote lab. In addition, a friendly interface has been designed including augmented reality to identify the different elements and to provide information on these items if the student requires it. The testing bench has been developed to be used in different kinds of electrical machines test