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Nowadays, several alternatives to internal combustion engines are being proposed in order to reduce CO2 emissions in freight transportation and citizen mobility. According to many experts, the use of electric vehicles constitutes one of the most promising alternatives for achieving the desirable reductions in emissions. However, popularization of these vehicles is being slowed by long recharging times and the low availability of recharging stations. One possible solution to this issue is to employ the concept of battery sharing or battery swapping. This concept is supported by important industrial partners, such as Eni in Italy, Ample in the US, and Shell in the UK. This paper supports the introduction of battery swapping practices by analyzing their effects. A discrete-event simulation model is employed for this study. The obtained results show that battery sharing practices are not just a more environmentally and socially friendly solution, but also one that can be highly beneficial for reducing traffic congestion.

Machine learning algorithms and the increasing availability of data have radically changed the way how decisions are made in today’s Industry. A wide range of algorithms are being used to monitor industrial processes and predict process variables that are difficult to be measured. Maintenance operations are mandatory to tackle in all industrial equipment. It is well known that a huge amount of money is invested in operational and maintenance actions in industrial gas turbines (IGTs). In this paper, two variations of autoencoders were used to analyse the performance of an IGT after major maintenance. The data used to analyse IGT conditions were ambient factors, and measurements were performed using several sensors located along the compressor. The condition assessment of the industrial gas turbine compressor revealed significant changes in its operation point after major maintenance; thus, this indicates the need to update the internal operating models to suit the new operational mode as well as the effectiveness of autoencoder-based models in feature extraction. Even though the processing performance was not compromised, the results showed how this autoencoder approach can help to define an indicator of the compressor behaviour in long-term performance. This research was funded by Siemens Energy.

The paper presents a set of prototype smart grid technologies and services and validates the economic viability of the proposed solution using cost–benefit analysis (CBA). The study considered the EU-funded project called RESOLVD and implemented the technologies and services in a real-life pilot. the technologies and services on the EU-funded H2020. The paper focuses on the analysis of technological solutions which enhance the operational efficiency and the hosting capacity of low-voltage electricity distribution grids. The solutions provided better integration of a hybrid battery storage system, with the grid interfacing power electronics, smart gateways for the interconnection of assets at the grid edge, and sensors enhancing infrastructure observability and control. The result from the CBA indicates the economic viability of the project, high scalability, and replicability. The economic benefits were realized with the breakeven value of eight secondary substations (SS) and 16 feeders. The scenario test on the DSO’s willingness to pay for the software as a service (SaaS) revealed that the payback period can further be reduced by almost half with a higher internal rate of return (IRR) and net present value (NPV). Both the CBA and scenario tests showed RESOLVD solution can become more economically viable when deployed in largescale. Moreover, the CBA results provide evidence to the energy policy by allowing DSOs to consider both CAPEX and OPEX for better investment decisions. Further, the paper proposes an alternative business approach that shifts from grid reinforcement to service provision. The paper also discusses the research implications on energy policy and business. Peer Reviewed Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles

INTRODUCCION: La hidroelectricidad es una fuente renovable ampliamente usada; en el ano 2016, un total de 159 paises reportaron beneficiarse, actualmente existen alrededor de 9,000 proyectos en funcionamiento debido al costo competitivo al generar a un costo similar como la energia termica como el carbon, petroleo o gas en el rango de USD 4 – 5 centavos de dolar americanos por kilovatio hora. OBJETIVO: Indagar los resultados del desarrollo hidroelectrico frente al clima cambiante e impactos que se generan, volviendo a la hidroenergia un subsector de especial atencion para discutir la proyeccion global. METODO: Revision bibliografica para reflexionar en base a estudios cientifica el contexto global de la hidroelectricidad. RESULTADOS: La hidroelectricidad proyecta una disminucion para Europa en 6% para el ano 2070, del 20% al 50% en todo el Mediterraneo, y, reduccion de la capacidad utilizable en la mayoria de plantas hidroelectricas entre el 61% para el escenario 2040–2069 globalmente. DISCUSION Y CONCLUSIONES: Globalmente la hidroenergia presenta una vision amplia de las ventajas y poco se habla de las desventajas y problemas, debido a que solo existen estudios especificos de diversos proyectos estudiados de forma general. Se demuestra que la produccion hidroelectrica tiene varias implicaciones frente al clima cambiante e impactos que se generan en los ecosistemas por el despliegue de grandes infraestructuras.

The increasing penetration of Large-Scale Photovoltaic Power Plants in the power system is raising the concern of potential stability issues due to dynamic interactions of power electronics components. In particular, Power Plant Controllers are starting to provide a fast dynamic response for specific services, such as fast frequency response, which could trigger unexpected unstable interactions with the PV inverters or other grid components. Also, an eventual reduction of synchronous generation in the grid could lead to a power system with high penetration of power electronics, which presents unexplored stability problems. This paper presents an interaction and stability study of a Photovoltaic Power Plant connected to the grid. This study is based on a small-signal analysis employing eigenvalues and participation factors to identify potential unstable modes. A linear model of the Photovoltaic Power Plant is implemented to apply a small-signal analysis. This linear model is validated with the equivalent non-linear model based on time-domain simulations in Matlab Simulink. 2022 The Author(s) The work of Oriol Gomis-Bellmunt is supported by the ICREA Academia program. Marc Cheah-Mane, Eduardo Bullich-Massague and Eduardo Prieto-Araujo are Lecturers of the Serra Hunter programme. This work is also supported under the umbrella of SOLAR-ERA.NET Cofund, which includes the Ministry of Economy and Competitiveness, the CDTI and the Swedish Energy Agency. SOLAR-ERA.NET is supported by the European Commission within the EU Framework Programme for Research and Innovation HORIZON 2020 (Cofund ERA-NET Action, no. 691664 ) This work was supported by the National Priorities Research Program under Grant 11S-1125-170027 from the Qatar National Research Fund (a member of Qatar Foundation ). Scopus 2-s2.0-85124150691

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works This paper presents an Multi-Input Multi-Output (MIMO) analysis to investigate the mutual interactions and small-signal stability of bipolar-type dc microgrids. Since bipolar dc microgrid is replete with power-electronic converters, its dynamics can not be understood unless the interactions among control systems of converters are properly investigated. To tackle the challenge, each converter in microgrid is modeled via an MIMO transfer matrix. Then, the MIMO models are combined together based on the interactions among the control systems of source and load converters. From this integrative MIMO model, the mutual interactions between various input-output pairs are quantified using Gershgorin Band theorem. Also, Singular Value Decomposition (SVD) analysis is carried out to estimate the frequency of unstable poles. Test results not only successfully validate the effectiveness of the MIMO method but also show that the control system of voltage balancer has a major impact on the overall stability of bipolar dc microgrid, making it a suitable location for applying damping systems.

Electrical production for residential areas is one of the most important goals of SDGs (17 UN goal) and UN-Habitat III (14 goals) that can be achieved by renewable energy. Now, renewable energy is a significant issue that must be considered seriously as a policy and in order to achieve energy sustainability on a global scale especially in whole developing countries. Also, since the role of renewable energy in sustainable development is remarkable, thus this article presents a comprehensive discussion of energy sustainability for urban areas with related energy indicators and technical analysis of a Hybrid Power System to show the importance of renewable energy to gain energy sustainability. This paper presents the feasibility of using PV-DG hybrid systems as the reliable energy by an economic and technical analysis in one of the southern cities of Iran use of HOMER software. Regarding the high average of solar radiation that is about 5.4 kWh/m2/d in Chabahar city, technical analysis of this system demonstrates that this city has a high capacity to producing the electrical energy via PV-diesel hybrid system with total electrical production amount of 10,575 kWh/yr from PV (8,447 kWh/yr) and Diesel system (2,128 kWh/yr). For do this work at the first, the required data is gathered from the meteorological organization of Iran and then technical and economic analysis is conducted with the Homer software. This study regarding the high potential of solar energy of Chabahar city shows that to achieve development especially in the energy sustainability field needs to implementing proper actions such as enough investment on clean energy and using renewable energy for electrical production.

Road transportation is heading towards electri fi cation using Li-ion batteries to power electric vehicles o ff ering eight or ten years' warrant. After that, batteries are considered inappropriate for traction services but they still have 80% of its original capacity. On the other hand, energy storage devices will have an important role in the electricity market. Being Li-ion batteries still too expensive to provide such services with economic pro fi t, the idea to reuse a ff ordable electric vehicle batteries for a 2nd life originated the Sunbatt project, connecting the automotive and electricity sectors. The battery reuse is, by itself, a path towards sustainability, but the clean- liness of energy storage also depends on the electricity generation power sources and the battery ageing or lifespan. This paper analyses the rest of useful life of 2nd life batteries on four di ff erent stationary applications, which are: Support to fast electric vehicle charges, self-consumption, area regulation and transmission deferral. To do so, it takes advantage of an equivalent electric battery-ageing model that simulates the battery capacity fade through its use. This model runs on Matlab and includes several ageing mechanisms, such as calendar ageing, C-rate, Depth-of-Discharge, temperature and voltage. Results show that 2nd life battery lifespan clearly depends on its use, going from about 30 years in fast electric vehicle charge support applications to around 6 years in area regulation grid services. Additionally, this study analyses the day-to-day emissions from electricity generation in Spain, and states that grid oriented energy storage applications will hardly o ff er environmental bene fi ts in the nearby future. On the other hand, applications that go by the hand of renewable power sources, such as self-consumption applications, are much more appropriate

The purpose of the paper is to introduce a new bi-directional approach to assess the gap between the customer needs and technology developers’ perception on the value propositions of innovations which includes storages. The paper used two methods, the first comprehensive sense and respond analysis investigated technology developers’ perceptions using the value propositions defined under the EU-funded H2020 RESOLVD project. The second method focused on customers and collected a survey which covered challenges, value propositions and preparedness to adopt new technology. The H2020 RESOLVD project has developed an intelligent low-voltage grid management system with storage. The results from the sense and respond analysis showed that most of the value propositions aligned with the responses from the broader survey which are needed within five years (e.g., improved power quality of grid, fault detection, reduced technical loss). However, the cybersecurity perception differed between developers and distribution system operators (DSOs). The customer survey highlighted that certain value propositions of technological solutions are needed more urgently than others, and therefore, technology developers should prioritize these in further developments. Regarding the use of flexibility to manage the LV grid, unclear regulations were expressed as a key barrier, thereby affecting business feasibility around battery storage.

Producción Científica, This paper shows an experimental application case to convert a part of the grid formed by renewable generation sources, storage systems, and loads into a smart microgrid. This transformation will achieve greater efficiency and autonomy in its management. If we add to this the analysis of all the data that has been recorded and the correct management of the energy produced and stored, we can achieve a reduction in the electricity consumption of the distribution grid and, with this, a reduction in the associated bill. To achieve this transformation in the grid, we must provide it with intelligence. To achieve this, a four steps procedure are proposed: identification and description of the elements, integration of the elements in the same data network, establishing communication between the elements and the control system, creating an interface that allows control of the entire network. The microgrid of CEDER-CIEMAT (Renewable Energy Centre in Soria, Spain) is presented as a real case study. This centre is made up of various sources of generation, storage, and consumption. All the elements that make up the microgrid are incorporated into free software, Home Assistant, allowing real-time control and monitoring of all of them thanks to the intelligence that has been provided to the grid. The novelty of this paper is that it describes a procedure that is not reported in the current literature and that, being developed with Home Assistant, is free and allows the control and management of a microgrid from any device (mobile, PC) and from any place, even though not on the same data network as the microgrid.

© 2022 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/ The use of the electrical energy storage (EES) plays an important role in the transition of energy generation towards renewable energy sources (RESs). An effective sizing of EES systems is very important in order to cope with the volatility of RESs and to ensure a reliable energy supply. The present paper provides a methodology which helps to determine the minimum required EES size for conceiving a fully standalone system. Its approach is based on the evaluation of the energy balance for a given design period, and it can also be applied for sizing the EES system in grid-connected applications. The methodology was validated using measurement data obtained from two different systems corresponding to: a) a near-zero energy building with local generation sources, and b) a large-scale battery energy storage system (BESS) installed in a factory and used for peak-shaving. The obtained results confirmed the effectiveness of the proposed methodology by estimating the required size of the EES system. A good correlation was found between the estimated and the installed BESS size in the considered systems. The deviation between real and estimated BESS capacities was found to be less than 5%. Peer Reviewed Objectius de Desenvolupament Sostenible::13 - Acció per al Clima Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant

El sector automovilístico está sufriendo un cambio respecto a la oferta de vehículos. La mayoría de marcas están apostando por campañas de oferta en las que resaltan el uso de vehículos eléctricos o híbridos enchufables. Parece que todo indica que empieza el relevo generacional de los vehículos clásicos de combustión por estos modelos con menores emisiones. Pero para poder llegar a dar este gran paso se necesita incrementar la infraestructura de puntos de recarga en todo el mundo. Para realizar este proyecto se realiza un estudio de los tipos de puntos de recarga para encontrar el más adecuado, sumado a toda la instalación eléctrica que le sigue para poder llevar a cabo su instalación y correcto funcionamiento. También se estudia su posible ubicación y simulado como encajaría llevado a la práctica la instalación El objetivo de este estudio es llevar a cabo un proyecto de instalación de un punto de recarga rápido en una estación de carretera cercano a un punto de alta afluencia de tráfico de vehículos dentro del territorio de Cataluña, teniendo en cuenta la existencia de otros puntos de recarga ya existentes en este territorio y dando soporte a zonas que no dispongan de uno de estos en un rango cercano. de esta estación de recarga. Todo ello nos lleva a observar la viabilidad del proyecto y tener los resultados necesarios para poder llevarlo a cabo. Teniendo todos los datos en cuenta, hay que resaltar la capacidad y viabilidad de reproducir proyectos como el realizado en este estudio, con adaptaciones respecto las previsiones de cargas de cada caso, y teniendo en cuenta las velocidades de cargas deseadas por el instalador de los puntos de recarga.

INTRODUCTION: Hydropower is an extensively used renewable source; in 2016, 159 countries reported benefiting; currently, there are around 9,000 projects in operation due to the competitive cost of generating a similar cost such as thermal energy such as coal, oil, or gas in the range of USD 4 - 5 cents US dollars per kilowatt-hour. OBJECTIVE: Investigate the results of hydroelectric development in the face of the changing climate and the generated impacts, making hydropower a subsector of special attention to discussing the global projection. METHOD: Bibliographic review to reflect on the global context of hydroelectricity based on scientific studies. RESULTS: Hydropower projects a 6% decrease for Europe by 2070, from 20% to 50% throughout the Mediterranean, and a reduction in usable capacity in most hydroelectric plants between 61% for the 2040 scenario– 2069 globally. DISCUSSION AND CONCLUSIONS: Globally, hydropower presents a broad vision of the advantages, and little said about the disadvantages and problems, and only there are specific studies that shown various project studied in a general way. It is shown that hydroelectric production has several implications in the face of the changing climate and impacts generated in ecosystems by the deployment of large infrastructures.

Ponencia presentada en: IEEE International Conference on Environment and Electrical Engineering and 2021 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe), del 7 al 10 de septiembre de 2021 The use of permanent magnet synchronous generators (PMSGs) with full-scale back-to-back converters is rising as a common option in wind power generation systems (WPGSs). An efficient grid integration of PMSG-WPGSs is obtained through quasi-Z-source inverter (qZSI). Simultaneously, power electronic system integration concerns related to dynamics have arisen. Power electronics reduce damping of grid-connected converters, leading to dynamic issues. Several studies focus on qZSI dynamics, but the analysis of qZSI based PMSG-WPGS dynamics to evaluate transient interactions is not yet well addressed. This paper studies a qZSI based PMSG-WPGSs small-signal state-space model for Matlab/Simulink implementation in order to study these concerns. The model is applied to investigate qZSI based PMSG-WPGS dynamic response and it allows the influence of components and parameters on system dynamics to be assessed. Eigenvalues are obtained from the state-space model in order to study qZSI based PMSG-WPGS stability and the participation factors are also analyzed to find out the most influential circuit component or control on the different eigenvalues. PSCAD/EMTDC simulations are made to test the model.

The final publication is available at Springer via http://dx.doi.org/10.1007/s12053-020-09915-y This paper presents a new energy efficiency-based classification approach for street lighting. This approach considers the improvement of visual performance by correcting the standard photometry system (photopic) by the mesopic system, recommended within the CIE 191:2010 and the operational hours of the lighting system, aspects that are usually disregarded by the most-used energy classifications. The method proposed here is based on the value function concept, which allows standardizing an energy performance indicator, representing a satisfaction degree. To validate the approach proposed, a case study in 13 representative streets of the Eixample District of Barcelona is carried out, comparing results with those obtained by other three energy efficiency classifications used in Spain, Netherlands, and Italy. These results derived from the application of the method supports decision-making when using different energy classifications and straightforward to quantify potential energy savings.

The automotive sector is rapidly accelerating its transformation towards electric mobility, and electric vehicle (EV) sales have been increasing year after year since the beginning of the decade. Due to their overall performance, lithium-ion batteries currently dominate the electric vehicle market. Each year, car manufacturers launch new models, increasing the average capacity of electric vehicle batteries. This is achieved, in part, through making bigger batteries, which lead to an increase in the vehicle cost, weight and use of more critical raw materials. Although prices are lowering, Li-ion batteries still do not have enough energy density to substantially decrease the weight of vehicles, and EVs are around 50% heavier than common internal combustion engine vehicles (ICEV); thus, using high-energy cells is an intriguing possibility that we are being called on to explore. This Special Issue aims to evaluate several issues concerning high-capacity batteries Peer Reviewed Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant

En el present treball de final de grau es descriuran les característiques tècniques de les instal·lacions necessàries per tal de realitzar la millora de la xarxa existent d’alta tensió. Es treballarà sobre tres suports i consistirà en un canvi de seccionador convencional per seccionador telecomandat encapsulat en SF6 (suport A), en els següents suports es realitzarà un canvi dels suports existents de fusta per dos torres metàl·liques amb conversió aeri - subterrani amb entrada en el suport B i sortida del tram subterrani en el suport C. In this end-of-degree project, installations' technical characteristics necessary to carry out an improvement of the existing high voltage network will be described. Job will be performed on three supports consisting of, on one hand, a change from a conventional disconnector to a remote-controlled disconnector encapsulated in SF6 (support A) and, on the other hand, the existing wooden brackets will be replaced for two metal towers with overhead to underground transition on support B input together with an underground output on support C.

Blockchain technology has been gaining increasing attention in the energy sector, where one of its most promising application seems to be Peer-to-Peer (P2P) energy trading. Several startups and power companies are running proof-of-concept and pilot projects all over the world to test this specific use case. However, despite a lot of work being done to address the technical and regulatory aspects related to P2P energy trading, our understanding of the human aspects affecting the adoption of this new paradigm for decentralized power supply is still very limited. The development of a decentralized energy market poses interesting challenges to the HCI community and raises important questions that need to be answered: What is the perceived usefulness of P2P energy trading? Do people understand this new paradigm? Are they aware of their role as market players? In order to dive deep into people understanding of P2P energy trading, this project aims at designing and testing the effectiveness of several ways of representing the complex dynamics behind energy consumption, production and exchange. The expected output consists identifying a set of guidelines for designing P2P energy trading platform and foster users understanding and engagement in the decentralized energy market.

In this paper, a novel two-phase linear hybrid reluctance actuator with the double-sided segmented stator, made of laminated U cores, and an interior mover with permanent magnets is proposed. The permanent magnets are disposed of in a way that increases the thrust force of a double-sided linear switched reluctance actuator of the same size. To achieve this objective, each phase of the actuator is powered by a single H-bridge inverter. To reduce the detent force, the upper and the lower stator were shifted. Finite element analysis was used to demonstrate that the proposed actuator has a high force density with low detent force. In addition, a comparative study between the proposed linear hybrid reluctance actuator, linear switched reluctance, and linear permanent magnet actuators of the same size was performed. Finally, experimental tests carried out in a prototype confirmed the goals of the proposed actuator.

The continuous increase of electric demand , the necessity to establish and integrate renewable energy sources in the power mix and the momentum of European energy operators to create a consolidated European energy market ,has created the need to expand the European energy grid ,with the construction of new transmission lines. The aim of this this project is to estimate the cost of the transmission lines that are planned to be constructed in Europe in the next ten years, so stakeholders can understand the magnitude and the objective of these projects. This bachelor thesis presents a technical-economic analysis of the different type of transmission technologies that are going to be assembled ,all over Europe, in the near future.From the conventional HVAC over head lines, to the cutting edge technology of VSC based HVDC lines.The basics of these technologies will be studied in order to understand and create the different cost models that are going to be used. Some of the models will be gathered from reports and studies and then expanded, in order to adapt the models to the European scene, while other models will be self-made using regression methods. In the purpose of studying the future European power grid, the information presented by ENTSO-E on the Ten Year Network Development Plan 2018, will be taken in account.Cost models will be applied to each of the published projects in TYNDP2018 using a self made algorithm that is based cost models to the information obtained from TYNDP2018

This thesis addresses the control of multiterminal HVDC grids based on voltage-source converters interconnected via high-voltage DC/DC converters. In particular, it presents a new methodology to conceive a linear model of the aforementioned system taking into account the state of the art techniques. The grids are controlled by means of a current-based droop control designed through a multivariable frequency analysis considering the grid specifications. Furthermore, PI current controllers tuned by the internal model control technique are used for controlling the DC/DC converters. The model’s performance is evaluated and compared to its equivalent non-linear model through simulations of a case study employing actual infrastructure data

El model de distribució elèctrica es troba en estat de canvi. Degut a la necessitat de transició a un model de generació elèctrica menys depenent de combustibles fòssils i la tendència a apostar per fonts d’energia renovables, cal deixar enrere el model convencional de distribució a través de la xarxa centralitzada. Per garantir la incorporació d’aquestes fonts renovables de manera òptima a la xarxa utilitària es requereix de sistemes de control que permetin intercanviar potència de manera eficient. Aquest projecte tracta l’estudi dels elements i del disseny d’una microxarxa basada en energia solar fotovoltaica fent ús d’invertidors elèctrics de corrent continu a altern de tipus VSC (Voltage Source Converter). Aquests sistemes poden operar tant de manera aïllada com connectada a la xarxa utilitària. Mitjançant un sistema de control descrit en aquesta memòria, es permet intercanviar potències actives i reactives de manera bidireccional i controlada. Per tal d’optimitzar l’energia produïda pel sistema modelitzat s’ha presentat algoritmes MPPT (Maximum Power Point Tracking) que permeten operar al sistema generant la màxima potència per a unes condicions determinades. Mitjançant el software Simulink s’ha validat tots els dissenys descrits mitjançant simulacions per a diferents tipus de microxarxa i s’ha analitzat la resposta del sistema per a diferents condicions.

Modern electrical networks are continuously evolving due to the increasing deployment of Information Technologies and Distributed Energy Resources (DERs). This scenario affects the quality of the electricity supply of distribution systems. For this reason, this quality plays a key role on the evolution of electrical networks into Smart Grids. Quality of the electricity supply is defined through three main skills: reliability of the electric power system, power quality and customer relationships, all of them under safety layer. From the network operation point of view, availability in a distribution network is crucial to maintain reliability. Fault location is a priority for electrical network operators in their efforts to ensure high quality for loads, generators and prosumers. The presence of DERs in current electrical distribution networks poses a new scenario where bidirectional current flow complicates fault detection. Implementation of the Smart Grid concept in these networks depends on the automation of procedures such as Fault Location, Isolation and Service Restoration, which enable a rapid response to faults. This paper proposes a fault detection algorithm for grid topologies such as radial, ring, meshed with or without DER penetration.

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. An accurate electricity price forecasting (EPF) plays a vital role in the deregulated energy markets and has a specific effect on optimal management of the power system. Considering all the potent factors in determining the electricity prices—some of which have stochastic nature—makes this a cumbersome task. In this article, first, Grey correlation analysis is applied to select the effective parameters in EPF problem and eliminate redundant factors based on low correlation grades. Then, a deep neural network with stacked denoising auto-encoders has been utilized to denoise data sets from different sources individually. After that, to detect the main features of the input data and putting aside the unnecessary features, dimension reduction process is implemented. Finally, the rough structure artificial neural network (ANN) has been executed to forecast the day-ahead electricity price. The proposed method is implemented on the data of Ontario, Canada, and the forecasted results are compared with different structures of ANN, support vector machine, long shortterm memory—benchmarking methods in this field—and forecasting data reported by independent electricity system operator (IESO) to evaluate the efficiency of the proposed approach. Furthermore, the results of this article indicate that the proposed method is efficient in terms of reducing error criterion and improves the forecasting error about 5–10 percent in comparison with IESO. This is a remarkable achievement in EPF field.

The chapter deals with energy efficient envelope tracking solution in a power amplifier system for demanding wireless standards.

In the past decade, a new technology has born that is currently on the way to revolutionize the transport industry of the 21st century. Drone industry has shown an extreme growth in the past years and it is expected to increase even more in the following years. As the market is increasing, the demand and the requirements are growing too, which means the industry needs to provide the customers market-ready all-round solutions for any kind of applications. Since the drone technology is reaching its mature phase, a well-designed drone logistics technology (drone docking and charging station, control station, etc..) would be needed to offer a full solution to the customer. After analyzing the current drone charging station market, the following conclusion has been made: a few mono-drone charging solutions have already penetrated the market, but due to the limitations of such systems, these solutions do not fulfill the requirements of most of the customers. At the same time, the market of the multidrone charging stations is nearly untouched, only a few prototypes have been shown, which means a significant opportunity for new market entries. This thesis was aimed to introduce the reader to the prototype of the world’s largest multi-drone charging and control station, the V-Station (or Vertical Station), created by EVA Inc. This innovative solution provides 6 separated landing and charging area (each 2.8 m2 ) at 3 different levels, in order to be able to manage any kind of drone fleet for any kind of missions. The reader gets insight into the design phase of the power system of the first prototype of V-Station, starting from the investigations of power supply possibilities, mentioning the preliminary calculations, the design of load profiles, the component selection, the system sizing calculations, the setup of simulations and finishing with the conclusions drawn from the simulation results. Taking into consideration the requirements of the pilot project and the need of customers, the following three power supply concepts have been designed and prepared for the application: On-grid System, Limited Standalone System, Fully Standalone System. After executing various iterations of simulations, the final system configurations have been defined. As a result of this work, the 3 power supply system concepts have been successfully created and prepared for implementation, which allows the company to place VS0001 prototype into operation and this way introduce the world’s largest drone charging station to the market.

Els sistemes elèctrics funcionen sota un llarg nombre de criteris i restriccions, però per sobre de tot hi ha una premissa bàsica. En cada instant de temps, la generació ha de ser igual a la demanda. La necessitat de generar en cada moment la mateixa energia elèctrica que es consumeix planteja un repte per a la introducció de les tecnologies renovables. El repte de les renovables és encara més gran quan no es pot obtenir una generació auxiliar d’un sistema proper en cas de necessitat. Aquest és el cas de les illes i dels sistemes aïllats. Al no disposar de connexió amb altres sistemes que puguin proveir de generació extra, moltes illes basen completament la seva generació en recursos fòssils, que donen seguretat de subministrament de manera ininterrompuda. L’objectiu d’aquest projecte serà determinar un sistema en illa concret i explicar com introduir-hi l’energia solar fotovoltaica. Al fer-ho esglaonadament i pas a pas, serà possible seguir el mateix procediment per a diferents casos, obtenint així sistemes híbrids de renovables i recursos fòssils. El procediment que s’ha seguit es el següent: En primer lloc, elecció de la localització (Ceuta), estudi de la demanda, estudi de la generació actual i avaluació del terreny. Un cop fets aquests passos es pot determinar un objectiu a assolir. Un cop determinat l’objectiu, es dimensiona el camp solar, es determinen els elements que el conformaran i es determina com funcionarà el sistema. Seguint aquests passos, es podrà introduir la tecnologia solar fotovoltaica en altres illes o sistemes aïllats. En la resolució del cas escollit, l’objectiu principal ha estat reduir les emissions al màxim però sempre amb un enfoc realista. Un projecte massa ambiciós pot no realitzar-se mai, deixant-ne així la reducció d’emissions a 0. Els resultats obtinguts de l’estudi a Ceuta indiquen una reducció de les emissions associades a la generació d’energia elèctrica de fins a un 35% sense ús de bateries. Tot i que en aquest projecte no es facin servir bateries, s’elaboren eines en aquest estudi per tal de poder veure com funcionaria aquesta o altres instal·lacions si s’hi introduïssin. D’aquesta manera, s’han definit una sèrie de passos a l’hora d’instal·lar l’energia solar fotovoltaica en un sistema basat en l’ús dels recursos fòssils. En aquest cas, s’ha obtingut una reducció significativa de les emissions amb un procediment que sempre ha buscat el realisme i l’aplicabilitat.

This study was developed based on the INVADE architecture, and its main objective is to present an algorithm to manage uncertainties of consumption and production in-between the FO instructions, for complying with the required flexible services. In this case the scope is limited to congestion management requirements from the DSO, but the algorithm allows for improvements to add new functionalities. The proposed algorithm works slightly modifying the FO instructions in order to expand the use of flexibility to manage the congestion events. The study is organized first by introducing the concepts related to flexibility in an electric system and the actors that could need flexibility services. Then an overview is done of the current architecture operation and the information exchanges between the actor that require a service (in this case the DSO) and the FO, presenting this way the main concerns of this study. Then, this document presents the definitions of the flexible sources that will be used for the development of the algorithm, the methodology that will be carried out and the structure of the input information. In general terms, the study consists of developing the algorithm in python capable of simulating power flows on a network to determine the best way to allocate flexibility. The algorithm is then described together with the equations and mechanisms used for the flexibility allocation. A simple example has been made to explain the basics of its functioning. Then the definition of a base scenario is presented, describing the topology of the network, the characteristics of the lines and transformers and of those inflexible and flexible sources that are part of it. The assumptions of the grid behavior (demands, solar radiations for PV panels, and connection status of EV’s) and the FO instructions for the flexible sources are also given. Finally, the simulation is run and the results are analyzed, also describing the operation of the algorithm in a particular period for a complete understanding. The algorithm effectively uses the available flexibility to eliminate congestions on the network, limiting the loading percentages of lines and transformers to a predefined value. It also uses the available capacity on lines and transformers to apply downwards regulation and thus minimizing de differences with the FO instructions. The proposed algorithm allows for the reduction of infrastructure expansion costs and provide valuable information for promoting the use of flexible sources in a certain sector of the network.

L’electrotècnia és l’estudi dels circuits elèctrics que permet conèixer fenòmens elèctrics, el comportament dels circuits estudiats, preveure el seu desenvolupament i utilitzar aquest estudi amb propòsits científics o industrials. Aquesta s’estudia amb diferents lleis i mètodes i es pot dividir en dos grans grups: els conceptes monofàsics (fonamentals per a la resta d’estudis) i els conceptes trifàsics. Els sistemes monofàsics són aquells en els que els circuits s’alimenten a través de dos conductors (en corrent altern, a través d’una fase i del conductor neutre), són els majoritàriament utilitzats en instal·lacions elèctriques de petits consumidors. Els sistemes trifàsics són aquells en els que els circuits s’alimenten a través de tres conductors (en corrent altern, a través de tres fases) o tres conductors i del conductor neutre, són els majoritàriament utilitzats en instal·lacions elèctriques de generació i distribució així com grans consumidors. L’objectiu del present TFG és el desenvolupament i realització d’una eina informàtica en l’entorn MATLAB que permeti als estudiants de l’ETSEIB treballar de manera gràfica i clara amb els conceptes en règim monofàsic més importants que s’adquireixen a l’assignatura d’electrotècnia així com l’estudi i aplicació del mètode dels nusos. Per a assolir aquest objectiu s’ha dividit en dues parts el treball realitzat, una teòrica i una pràctica. La part teòrica té com a objectiu la introducció i la explicació dels nous conceptes i per a la seva exposició han estat necessaris els conceptes adquirits en el moment que es va cursar l’assignatura. Pel que fa a l’objectiu de la part del programa, ha estat per una millor claredat i visualització a l’hora de l’estudi dels conceptes exposats. Aquest programa s’ha enfocat especialment als estudiants ja que pretén ser una eina didàctica que faciliti la comprensió d’alguns conceptes importants de l’electrotècnia. A través d’aquest, l’usuari disposa de diferents exemples o explicacions amb els corresponents resultats per a que pugui comprovar si és capaç d’aplicar correctament els diversos mètodes estudiats.

Como consecuencia a los diferentes y graves problemas que se presentan por parte de las energías convencionales, las alternativas cada vez se encuentran con más protagonismo en la obtención de la electricidad. Esta importancia se ve reflejada en un uso considerable de las más notorias y en el estudio de renovables nuevas en referencia a su aprovechamiento. Entre estas se puede destacar la energía undimotriz, la cual se produce gracias al movimiento de las olas. En la actualidad, existen varios proyectos centrados en convertirla en una energía eficiente y confiable, así como en implantarla y tenerla presente junto con las más utilizadas, la hidroeléctrica, la eólica y la solar. El objetivo de este proyecto es aportar a estas investigaciones una estrategia capaz de sacar unas primeras conclusiones en cuanto a potencia eléctrica a partir de las características del oleaje. Tras el estudio del modelo de la ola trocoidal y la determinación de los modelos mecánicos y eléctricos de las partes que comprende un generador eléctrico, los parámetros desconocidos presentes en estos son conseguidos gracias a un ensayo eléctrico – mecánico, donde se muestra las principales partes del captador de energía que se propone para realizar este estudio teórico. Tras realizar este ensayo y comparar los resultados de la lectura de datos reales, los cuáles muestran la intensidad de corriente y ángulo desplazado del eje que se comunica con el rotor, con los resultados que arrojan los modelos, estos se aprueban dadas las similitudes y se establecen como válidos para los generadores eléctricos con características parecidas al utilizado en la prueba. Observando las gráficas de potencia extraída respecto al ángulo desplazado para diferentes cargas eléctricas, se extrae una ecuación general que relaciona estos factores. Tras examinar los modelos conjuntamente en una situación real, como un sistema de ecuaciones diferenciales, se observa que los resultados muestran un sentido físico y por lo tanto se pueden aprobar como útiles para un análisis teórico de esta energía renovable.

L’objecte del present d’energia renovables treball consisteix en l’estudi de la integració a gran escala de fonts (eòlica i solar) en la xarxa elèctrica. Això representa un gran desafiament a causa de la incertesa d’aquests recursos ja que pateixen grans variacions i sobretot, sobtades. Es pretén, per tant, efectuar una anàlisi comparativa de diferents mesures de flexibilitat existents com poden ser una estació de bombament, una estació de bateries, una resposta a la demanda o bé una planta virtual, encaminades a augmentar el grau d’integració a la xarxa elèctrica de l’electricitat provinent d’aquestes fonts renovables. Aquestes mesures s’utilitzaran per tal d’assegurar la operació eficient i segura del sistema elèctric en escenaris d’elevada penetració renovable. Les fonts renovables es complementen amb les fonts de generació convencional i de biomassa. Aquest estudi s’ha realitzat amb la modelització mitjançant el programari AIMMS. Com a conclusió es pot veure que totes les opcions de flexibilitat disminueixen, en major o menor grau, el vessament de les fonts renovables i per tant s’obté més quantitat d’energia renovable aprofitada. Aquest fet ajuda a aconseguir minimitzar l’efecte de la variabilitat de les renovables.

El estudio de las resonancias en circuitos eléctricos es fundamental puesto que este fenómeno puede llevar a valores de voltaje o corriente elevados que podrían llegar a dañar el circuito o la instalación eléctrica. Existen diferentes métodos para analizar dicho fenómeno, pero su aplicación no es sencilla. A la hora de estudiar la resonancia, las respuestas a las siguientes preguntas podrían revelar información importante que sería de gran ayuda: ¿Cuál es la frecuencia a la cual ocurre la resonancia? ¿Cuál es la zona del circuito más sensible a la resonancia? ¿Desde qué punto del circuito se puede observar mejor el fenómeno? ¿Cuál es el elemento del circuito que más influye en la resonancia? Las repuestas a muchas de estas preguntas no se pueden determinar fácilmente con los métodos tradicionales para el estudio de las resonancias. Recientemente, ha aparecido el método modal de análisis que, aplicado junto con del método de los nudos, es capaz de resolver todas las cuestiones anteriores. Este trabajo estudia el fenómeno de la resonancia a partir del método modal de análisis. En primer lugar, se presenta su deducción desde el método de los nudos y luego se explica cómo localiza y analiza el fenómeno de la resonancia en circuitos eléctricos. Tras el estudio de este método, el trabajo concluye con la creación de un programa en Matlab que aplica el método modal de análisis a cualquier circuito eléctrico y sistemáticamente nos devuelve los parámetros relevantes para el estudio de la resonancia.

The application of Artificial Intelligence techniques in industry equips companies with new essential tools to improve their principal processes. This is especially true for energy companies, as they have the opportunity, thanks to the modernization of their installations, to exploit a large amount of data with smart algorithms. In this work we explore the possibilities that exist in the implementation of Machine-Learning techniques for the detection of Non-Technical Losses in customers. The analysis is based on the work done in collaboration with an international energy distribution company. We report on how the success in detecting Non-Technical Losses can help the company to better control the energy provided to their customers, avoiding a misuse and hence improving the sustainability of the service that the company provides.

Anti-islanding detection methods have been part of a secure operation for distributed energy resource inverters, avoiding the creation of non-intentional energization when the mains are lost. These detection mechanisms were conceived historically for current-controlled inverters. New control possibilities have broken ground, and current- or voltage-controlled inverters are a reality, however, special attention must be paid to detection strategies when applied to the latter ones. This paper addresses two topics: it exposes the lack of effectiveness of those detection algorithms based on the voltage/frequency displacement concept under voltage-controlled inverters and evaluates the applicability limits of the others based on the impedance measurement (IM). The IM is presented as a valid mechanism to achieve the islanding detection, but the exploration of its limits drives the concept of detection frequency bandwidth (DFBW), introduced in this paper. The DFBW is suggested as a practical approach to select the proper injection frequency to measure. Therefore, an improved strategy based on the IM and DFBW is proposed to allow achieving the detection towards (non-)resonant loads considering low computational burden. The results were experimentally validated in a 90-kVA four-wire voltage-controlled inverter, offering detection times of less than 100 ms in any case.

As a contribution to the study of the urban energy transition, this paper proposes a novel model of energy-economic evaluation of the cities self-sufficiency and presents its application in the form of a case study. The objective of this study was to analyse the scope of the investment in the photovoltaic self-consumption of buildings in order to promote the creation of Prosumers communities within the cities. The operation of this model is based on the scalability of the Nearly Zero Energy concept from buildings to cities and seeks to evaluate Nearly Zero Energy Cities (nZEC): cities made up of Nearly Zero Energy Buildings (nZEB) and other installations of distributed generation to cover their energy demand by use of local renewable resources to the detriment of external resources. By using public data, we apply this model with the aim of economically evaluating the investment of six packages of energy rehabilitation and photovoltaic self-consumption in 17% of the residential buildings (37,800) in the city of Barcelona. To do this, we simulated 37 years of electricity distribution among Consumers, Producers and a hypothetical peer-to-peer community of Prosumers during the period 2014–2050 in hourly time intervals. The results indicated that the photovoltaic self-consumption and the local markets of Prosumers help to reduce primary energy consumption, the energy costs, and the CO2 emissions.

Electric vehicles are becoming more and more popular. One of the most promising possible solutions is one where a hybrid powertrain made up of a FC (Fuel Cell) and a battery is used. This type of vehicle offers great autonomy and high recharging speed, which makes them ideal for many industrial applications. In this work, three ways to build a hybrid power-train are presented and compared. To illustrate this, the case of an industrial robot designed to move loads within a fully automated factory is used. The analysis and comparison are carried out through different objective criteria that indicate the power-train performance in different battery charge levels. The hybrid configurations are tested using real power profiles of the industrial robot. Finally, simulation results show the performance of each hybrid configuration in terms of hydrogen consumption, battery and FC degradation, and dc bus voltage and current regulation., This research was supported by the María de Maeztu Seal of Excellence to IRI (ref. MDM- 2016-0656) and the Spanish Ministry of Economy and Competitiveness under Project DOVELAR (ref. RTI2018-096001-B-C32).

Electric vehicles are considered the most promising alternative to internal combustion engine vehicles towards a cleaner transportation sector. Having null tailpipe emissions, electric vehicles contribute to fight localized pollution, which is particularly important in overpopulated urban areas. However, the electric vehicle implies greenhouse gas emissions related to its production and to the electricity generation needed to charge its batteries. This study focuses the analysis on how the electric vehicle emissions vary when compared to internal combustion engine vehicles, depending on the electric power plant fleet and the efficiency during the use-phase. For this to be done, the Global Warming Potential (GWP) associated to the electricity generation on the electric vehicle most selling European countries are calculated. Similarly, electric vehicle's use-phase energy efficiency is calculated under a wide range of driving conditions using the Monte Carlo method. The results from energy production and energy use-phases are compared to the GWP calculated for internal combustion engine vehicles for six different driving cycles, to obtain the threshold values for which electric vehicles provide GWP reduction. These threshold values are then matched with the current electricity power plant fleet and the electric vehicle promotion incentives of the European countries considered in the study, showing that some countries (e.g. France or Norway) are better-suited for electric vehicles adoption, while countries like Spain or Portugal should boost electric vehicle promotion policies. Furthermore, other countries in Europe, such as Germany or the UK that are doing an effort on decarbonizing their power plant fleet, do not offer immediate greenhouse gas emission reductions for the uptake of electric vehicles instead of conventional cars.

Under voltage sags, grid-tied photovoltaic inverters should remain connected to the grid according to low-voltage ride-through requirements. During such perturbations, it is interesting to exploit completely the distributed power provisions to contribute to the stability and reliability of the grid. In this sense, this paper proposes a low-voltage ride-through control strategy that maximizes the inverter power capability by injecting the maximum-rated current during the sag. To achieve this objective, two possible active power situations have been considered, i.e., high- and low-power production scenarios. In the first case, if the source is unable to deliver the whole generated power to the grid, the controller applies active power curtailment to guarantee that the maximum rated current is not surpassed. In the second case, the maximum allowed current is not reached, thus, the control strategy determined the amount of reactive power that can be injected up to reach it. The control objective can be fulfilled by means of a flexible current injection strategy that combines a proper balance between positive- and negative-current sequences, which limits the inverter output current to the maximum rated value and avoid active power oscillations. Selected experimental and simulation results are reported in order to validate the effectiveness of the proposed control strategy.

The increasing installation of photovoltaic panels in low-voltage grids causes an over voltage problem, especially during high production and low consumption periods. Generally the over voltage problem is overcome by implementing reactive power control methods. The advances in networked control systems theory and practice create new scenarios where reactive power control methods can offer additional features and benefits. To explore these new capabilities, this study presents two new reactive power control methods that exploit the networked approach. These two methods are evaluated in a comparative reference framework that also includes the base-line case where no reactive control method is applied, the conventional droop method approach, and a solution based on a near-optimal location of a high power STATCOM derived from one of the new proposed networked methods. The main merit factors used to compare the control methods are the maximum voltage across the distribution grid, the power factor in the point of common coupling, and the total power losses and economic cost of the installation. With these merit factors, the advantages and limitations of the new and existing control methods are revealed and discussed. A useful discussion for selecting the best control solution is also reported.

Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant

El motiu que impulsa presentar aquest projecte final de carrera és realitzar un estudi sobre les instal·lacions de posada a terra, centrant-se en la resistivitat del terreny i el propi elèctrode, investigant l’eficiència de les eines teòriques a l’hora d’afrontar casos pràctics i intentar optimitzar el factor més important: aconseguir el valor de resistència desitjat, fita que a vegades pot arribar a ser impossible per limitacions externes. En segon lloc, estudiar que aquest valor sigui estable amb el pas del temps, ja que es dona el cas que, amb el pas dels anys, moltes instal·lacions veuen el seu valor incrementat fins a nivells que poden posar en risc tant a la instal·lació a protegir com també a les persones, en cas d’un falla al sistema elèctric.

This paper presents a novel voltage sag topology that occurs during an unintentional islanding operation (IO) within a distribution network (DN) due to large induction motors (IMs). When a fault occurs, following the circuit breaker (CB) fault clearing, transiently, the IMs act as generators due to their remanent kinetic energy until the CB reclosing takes place. This paper primarily contributes to voltage sag characterization. Therefore, this novel topology is presented, analytically modelled and further validated. It is worth mentioning that this voltage sag has been identified in a real DN in which events have been recorded for two years. The model validation of the proposed voltage sag is done via digital simulations with a model of the real DN implemented in Matlab considering a wide range of scenarios. Both simulations and field measurements confirm the voltage sag analytical expression presented in this paper as well as exhibiting the high accuracy achieved in the three-phase model adopted.

The demonstrated existence of vast brine pools in a number of places in the ocean basin around the world offers an interesting opportunity to the production of power from ocean, which has not been yet considered. The attractiveness of these vast deposits of brine lie in the fact that can be readily dissolved with the surrounding top waters extracting the spontaneous osmotic mixing energy released. In addition, osmotic engines can pumped out the brackish streams by buoyancy without the add of pressure exchangers (PEXs) as is required in current pressure retarded osmosis (PRO) technology and then simplifying significatively the overall process. Utilizing a simplified physical model, a first estimation for the density of power per unit of membrane area was calculated

Des de l’aparició de la impremta moderna fa ja uns quants segles, aquesta tècnica de producció ha patit nombrosos canvis fins a convertir-se en una tècnica de disposició de materials i tintes precisa i eficaç. Caldria esmentar que fins l’actualitat moltes indústries han adoptat mecanismes de producció en massa amb els quals s’intenta, mitjançant una inversió inicial en equips i processos, aconseguir disminuir el cost unitari per producte i augmentar així la rentabilitat del procés a llarg termini. L’entorn industrial ha presentat, en aquests últims anys, símptomes d’un canvi en aquests processos productius. L’era digital ha impulsat aquestes tecnologies digitals a satisfer la creixent demanda de productes personalitzats i adaptats a cada tipus de consumidor. En un entorn en el que s’exigeixen processos de producció cada vegada més flexibles, amb menys estoc (producció just a temps), alta eficiència operacional, reducció de l’impacte mediambiental o la possibilitat de poder fabricar en lots o sèries curtes sense augmentar molt els costos, entre d’altres. Les àrees d’afectació d’aquesta tecnologia on resideixen nombroses de les seves aplicacions són la comunicació gràfica, l’empaquetat, la impressió funcional o les finalitats decoratives. L’objectiu principal d’aquest projecte és el de desenvolupar un pla de negoci per la implementació de la tecnologia d’impressió digital en el procés de producció d’interruptors domèstics i industrials d’una empresa estàndard. Es demostrarà la viabilitat de la idea de negoci plantejada i es dotarà el projecte de mesures i dimensions que s’adaptin a la realitat per així tenir uns índex de valor afegit respecte al procés industrial prèviament implementat. Primerament es realitzarà un estudi de mercat, de tecnologies ja funcionals i prototips, d’empreses competidores i de les tendències d’aquest sector que es reinventa dia a dia. Arribats a aquest punt es caracteritzarà el target de la empresa, segmentant el mercat i estudiant el nínxol trobat. Es realitzarà un posterior anàlisi operacional intern i extern de l’empresa, avaluant el canvi en el procés de fabricació dels productes. També s’estudiaran les noves responsabilitats i implicacions per a cada un dels departaments ja existents de l’empresa. Posteriorment es procedirà a un anàlisi de màrqueting i publicitat sempre de la mà d’un estudi financer que contemplarà les accions a prendre segons la inversió inicial i el període de retorn desitjat. Finalment, al tractar-se d’un marc en una era digital on les indústries i empreses han de reinventar-se cada dia per seguir el ritme d’evolució del sector, es plantejarà un model de Analítica de dades i Gestió de rendiment que permetrà transformar les dades en valor actiu per l’empresa. S’enfocarà aquest anàlisi en pronòstics, optimització de preus, optimització d’accions, projeccions i identificació dels indicadors claus o mesures de rendiment específiques. D’aquesta manera es buscarà desmarcar-se de la competència i analitzar les dades d’un sector en ple desenvolupament del qual encara no se’n coneixen amb exactitud les tendències ja que és relativament nou i en expansió.

The optimal management of distributed energy resources is one of the existing challenges for the deployment of microgrids. When microgrids operate under feeder flow control mode, trying to maintain a constant self-consumption, generators adapt their output power to compensate load and non-dispatchable generation variations. So, due to the uncertainty, finding the optimal operation point is an important task that can become complex. This paper proposes an optimal power flow problem formulation for feeder flow controlled microgrids. It iated as a mixed integer second order cone program considering the optimal power flow equations in its relaxed form and uncertainty by means of stochastic formulation. In addition, an algorithm is developed in order to find a feasible optimum solution of the original non-relaxed problem. The proposed algorithm can also be used in other optimal power flow problems with the condition that they must use the same relaxation. The algorithm is validated through the IEEE 33-Bus distribution test system.

Este documento desarrolla un proyecto real de renovación del alumbrado ornamental exterior de la Catedral de Palma de Mallorca. Centra sus esfuerzos en el análisis técnico de la instalación pero es fruto de un largo proceso de gestión de proyecto. Introduce el campo de la electricidad y las instalaciones de forma breve y desemboca en el dimensionamiento del proyecto completo. Finalmente enmarca los trabajos con un ensayo en laboratorio de una luminaria perteneciente al fabricante seleccionado para la adquisición de los elementos de instalación. Todo ello queda resuelto en la descripción técnica de una instalación de 649 proyectores controlados por diferentes protocolos de comunicación.

There has been an intensive research and development focus on lithium-ion batteries, which have revolutionized the electric vehicle market due to the batteries’ high energy and power density, longer lifespan, and increased safety than compa-rable rechargeable battery technologies. The performance of lithium-ion batteries is achieved by packaging design, electrolyte, and electrodes material’s selection. This study focuses on cathode materials as they currently need to overcome criti-cal challenges. In fact, cathode materials affect energy density, rate capability and working voltage that led to the cathode currently costing twice as much as the anode. For this reason, this study reviews cathode materials for electric vehicle lithium-ion batteries under economic and environmental perspectives to optimize the batteries’ structures and properties. Findings reveal that presently there is no commercially installed battery that can satisfy both, economic and environmental concerns while offering an overall excellent performance.