Investigación sobre la flexibilidad de la demanda en redes eléctricas inteligentes: control directo de cargas

In recent decades, the European Union has made decisive efforts to maintain its global leadership in renewable energies to meet climate change targets resulting from international agreements. There is a deliberate intention to reduce the usage of non-renewable energy sources and promote the exploitation of renewable generation at all levels as shown by energy production data within the Eurozone. The electricity sector illustrates a successful implementation of these energy policies: The electricity coming from combustible fuels was at historical lows in 2018, accounting for 83.6 % of the electricity generated from this source in 2008. By contrast, the pool of renewables reached almost 170 % of the 2008 production. Against this background, power systems worldwide are undergoing deep-seated changes due to the increasing penetration of these variable renewable energy sources and distributed energy resources that are intermittent and stochastic in nature. Under these conditions, achieving a continuous balance between generation and consumption becomes a challenge and may jeopardize the system stability, which points out the need of making the power system flexible enough as a response measure to this trend. This Ph.D. thesis researches one of the principal mechanisms providing flexibility to the power system: The demand-side management, seen from both the demand response and the energy efficiency perspectives. Power quality issues as a non-negligible part of energy efficiency are also addressed. To do so, several strategies have been deployed at a double level. In the residential sector, a direct load control strategy for smart appliances has been developed under a real-time pricing demand response scheme. This strategy seeks to minimize the daily cost of energy in presence of diverse energy resources and appliances. Furthermore, a spread spectrum technique has also been applied to mitigate the highfrequency distortion derived from the usage of LED technology lighting systems instead of traditional ones when energy efficiency needs to be improved. In the industrial sector, a load scheduling strategy to control the AC-AC power electronic converter in charge of supporting the electric-boosted glass melting furnaces has been developed. The benefit is two-fold: While it contributes to demand flexibility by shaving the peaks found under conventional control schemes, the power quality issues related to the emission of subharmonics are also kept to a minimum. Concerning the technologies, this Ph.D. thesis provides smart solutions, platforms, and devices to carry out these strategies: From the application of the internet of things paradigm to the development of the required electronics and the implementation of international standards within the energy industry.En las últimas décadas, la Unión Europea ha realizado esfuerzos decisivos para mantener su liderazgo mundial en energías renovables con el fin de cumplir los objetivos de cambio climático resultantes de los acuerdos internacionales. Muestra una intención deliberada de reducir el uso de fuentes de energía no renovable y promover la explotación de la generación renovable a todos los niveles, como demuestran los datos de producción de energía en la eurozona. El sector de la electricidad ilustra un caso de éxito de estas políticas energéticas: la electricidad procedente de combustibles fósiles estaba en mínimos históricos en 2018, representando el 83,6 % de la electricidad generada a partir de esta fuente en 2008; en cambio, el grupo de renovables alcanzó casi el 170 % de la producción de 2008. En este contexto, los sistemas eléctricos de todo el mundo están experimentando profundos cambios debido a la creciente penetración de estas fuentes de energía renovable y de recursos energéticos distribuidos que son de naturaleza variable, intermitente y estocástica. En estas condiciones, lograr un equilibrio continuo entre generación y consumo se convierte en un reto y puede poner en peligro la estabilidad del sistema, lo que señala la necesidad de flexibilizar el sistema eléctrico como medida de respuesta a esta tendencia. Esta tesis doctoral investiga uno de los principales mecanismos que proporcionan flexibilidad al sistema eléctrico: la gestión de la demanda vista tanto desde la perspectiva de la respuesta a la demanda como de la eficiencia energética. También se abordan los problemas de calidad de suministro entendidos como parte no despreciable de la eficiencia energética. Para ello, se han desplegado varias estrategias a un doble nivel. En el sector residencial, se ha desarrollado una estrategia basada en el control directo de cargas para los electrodomésticos inteligentes siguiendo un esquema de respuesta a la demanda con precios en tiempo real. Esta estrategia busca minimizar el coste diario de la energía en presencia de diversos recursos energéticos y electrodomésticos. Además, también se ha aplicado una técnica de espectro ensanchado para mitigar la distorsión de alta frecuencia derivada del uso de sistemas de iluminación con tecnología LED, empleados para la mejora de la eficiencia energética frente a las tecnologías convencionales. En el sector industrial, se ha desarrollado una estrategia de planificación de cargas para controlar el convertidor AC-AC de los hornos de fundición de vidrio con soporte eléctrico. El beneficio es doble: mientras que se contribuye a la flexibilidad de la demanda al eliminar los picos encontrados en los esquemas de control convencionales, también se reducen al mínimo los problemas de calidad de suministro relacionados con la emisión de subarmónicos. En cuanto a las tecnologías, esta tesis doctoral aporta soluciones, plataformas y dispositivos inteligentes para llevar a cabo estas estrategias: desde la aplicación del paradigma del internet de las cosas hasta el desarrollo de la electrónica necesaria y la implementación de estándares internacionales dentro de la industria energética

Estrategia de gestión energética en hornos eléctricos de resistencias incluyendo restricciones de calidad de suministro

Premio extraordinario de Trabajo Fin de Máster curso 2017/2018. Máster en Energías Renovables DistribuidasEn este trabajo se realiza una revisión acerca de los métodos de control de potencia más comúnmente empleados en hornos eléctricos de resistencias, profundizando en los basados en tiristores. Además, se advierte el problema de la existencia de grandes picos de demanda en determinados instantes generados como consecuencia de un consumo ineficiente y las consecuencias económicas y ambientales que esto supone. Para solventar este problema se propone un algoritmo de gestión energética que implementa acciones de respuesta a la demanda y de mejora de la calidad de suministro. Este se basa en el uso de la técnica “Integral Cycle Control” y en la distribución de los ciclos mediante el método del acumulador siendo su principal objetivo la reducción de la varianza en el perfil de demanda ya que, como se demuestra, se trata de la forma óptima.In this work, a brief review of power control methods for electric melting furnaces is given, focusing on those which are based on thyristors. Moreover, the problem of large peaks demand generated as a consequence of inefficient consumption and its economic and environmental consequences are highlighted. As a solution, an energy management system is proposed in order to implement demand response actions and improve the power quality. This solution is based on the use of the integral cycle control and on the distribution of the cycles by means of the accumulator method whose main objective is the reduction of the variance in the demand profile since, as it is demonstrated in this work, it is the optimal form

Energy Management Expert Assistant, a New Concept

In recent years, interest in home energy management systems (HEMS) has grown significantly, as well as the development of Voice Assistants that substantially increase home comfort. This paper presents a novel merging of HEMS with the Assistant paradigm. The combination of both concepts has allowed the creation of a high-performance and easy-to-manage expert system (ES). It has been developed in a framework that includes, on the one hand, the efficient energy management functionality boosted with an Internet of Things (IoT) platform, where artificial intelligence (AI) and big data treatment are blended, and on the other hand, an assistant that interacts both with the user and with the HEMS itself. The creation of this ES has made it possible to optimize consumption levels, improve security, efficiency, comfort, and user experience, as well as home security (presence simulation or security against intruders), automate processes, optimize resources, and provide relevant information to the user facilitating decision making, all based on a multi-objective optimization (MOP) problem model. This paper presents both the scheme and the results obtained, the synergies generated, and the conclusions that can be drawn after 24 months of operation

Demand and Storage Management in a Prosumer Nanogrid Based on Energy Forecasting

Energy efficiency and consumers' role in the energy system are among the strategic research topics in power systems these days. Smart grids (SG) and, specifically, microgrids, are key tools for these purposes. This paper presents a three-stage strategy for energy management in a prosumer nanogrid. Firstly, energy monitoring is performed and time-space compression is applied as a tool for forecasting energy resources and power quality (PQ) indices; secondly, demand is managed, taking advantage of smart appliances (SA) to reduce the electricity bill; finally, energy storage systems (ESS) are also managed to better match the forecasted generation of each prosumer. Results show how these strategies can be coordinated to contribute to energy management in the prosumer nanogrid. A simulation test is included, which proves how effectively the prosumers' power converters track the power setpoints obtained from the proposed strategy.Spanish Agencia Estatal de Investigacion ; Fondo Europeo de Desarrollo Regional

A Novel Direct Load Control Testbed for Smart Appliances

The effort to continuously improve and innovate smart appliances (SA) energy management requires an experimental research and development environment which integrates widely differing tools and resources seamlessly. To this end, this paper proposes a novel Direct Load Control (DLC) testbed, aiming to conveniently support the research community, as well as analyzing and comparing their designs in a laboratory environment. Based on the LabVIEW computing platform, this original testbed enables access to knowledge of major components such as online weather forecasting information, distributed energy resources (e.g., energy storage, solar photovoltaic), dynamic electricity tariff from utilities and demand response (DR) providers together with different mathematical optimization features given by General Algebraic Modelling System (GAMS). This intercommunication is possible thanks to the different applications programming interfaces (API) incorporated into the system and to intermediate agents specially developed for this case. Different basic case studies have been presented to envision the possibilities of this system in the future and more complex scenarios, to actively support the DLC strategies. These measures will offer enough flexibility to minimize the impact on user comfort combined with support for multiple DR programs. Thus, given the successful results, this platform can lead to a solution towards more efficient use of energy in the residential environment

Libro de Actas de las III Jornadas ScienCity 2020: Fomento de la Cultura Científica, Tecnológica y de Innovación en Ciudades Inteligentes

Editorial: Kindle Direct Publishing, Seattle, WS (USA)Actualmente, nuestras ciudades están experimentando una verdadera transformación digital que requiere una atención inmediata en energía, transporte, movilidad, comunicación, seguridad, educación, turismo y aspectos sociales, así como fomentar todas aquellas actuaciones que persigan mejorar la calidad de vida y el desarrollo económico-ambiental sostenible. ScienCity es un foro científico-tecnológico que pretende dar a conocer a la sociedad los conocimientos y tecnologías emergentes siendo investigados en las universidades, informar de experiencias, servicios e iniciativas puestas ya en marcha por instituciones y empresas, llegar hasta decisores políticos que podrían crear sinergias, incentivar la creación de ideas y posibilidades de desarrollo conjuntas, implicar y provocar la participación ciudadana.Junta de Andalucía, Universidad de Huelva y Consejo Social de la Universidad de Huelv