Water Management in PEM Fuel Cells: Controllability Analysis and Steady-state Optimization for Temperature Control

This paper presents a controllability study of the water management inside anode channel by regulating the stack temperature for PEM fuel cell systems with dead-ended anode. Moreover, this work includes the design of a steady-state target optimizer which calculates the temperature set-point profiles that minimize the stack degradation and the hydrogen leaks. The control architecture is successfully simulated and the results show promising performanc

Energy Demand Forecasting Using Deep Learning: Applications for the French Grid

This paper investigates the use of deep learning techniques in order to perform energy demand forecasting. To this end, the authors propose a mixed architecture consisting of a convolutional neural network (CNN) coupled with an artificial neural network (ANN), with the main objective of taking advantage of the virtues of both structures: the regression capabilities of the artificial neural network and the feature extraction capacities of the convolutional neural network. The proposed structure was trained and then used in a real setting to provide a French energy demand forecast using Action de Recherche Petite Echelle Grande Echelle (ARPEGE) forecasting weather data. The results show that this approach outperforms the reference Réseau de Transport d’Electricité (RTE, French transmission system operator) subscription-based service. Additionally, the proposed solution obtains the highest performance score when compared with other alternatives, including Autoregressive Integrated Moving Average (ARIMA) and traditional ANN models. This opens up the possibility of achieving high-accuracy forecasting using widely accessible deep learning techniques through open-source machine learning platforms

Solar Thermal Plants Integration in Smart Grids

Solar energy penetration has been increasingly growing in recent years. Since solar energy is intermittent its integration in existing grids is difficult. This paper deals with the optimal integration of solar power plants in grids. The paper proposes a modification of energy hubs which allows to solve the optimization problem with a mixed integer programming algorithm in a distributed way. An introductory simulation study case is givenMinisterio de Educación DPI2008-05818Junta de Andalucía P07-TEP-02720Comisión Europea HD-MP

Generic Framework for the Optimal Implementation of Flexibility Mechanisms in Large-Scale Smart Grids

This paper aims to provide the smart grid research community with an open and accessible general mathematical framework to develop and implement optimal flexibility mechanisms in largescale network applications. The motivation of this paper is twofold. On the one hand, flexibility mechanisms are currently a hot topic of research, which is aimed tomitigate variation and uncertainty of electricity demand and supply in decentralised grids with a high aggregated share of renewables. On the other hand, a large part of such related research is performed by heuristic methods, which are generally inefficient (such methods do not guarantee optimality) and difficult to extrapolate for different use cases. Alternatively, this paper presents an MPC-based (model predictive control) framework explicitly including a generic flexibility mechanism, which is easy to particularise to specific strategies such as demand response, flexible production and energy efficiency services. The proposed framework is benchmarked with other non-optimal control configurations to better show the advantages it provides. The work of this paper is completed by the implementation of a generic use case, which aims to further clarify the use of the framework and, thus, to ease its adoption by other researchers in their specific flexibility mechanism applications

Desarrollo y validación de un modelo dinámico para una pila de combustible tipo PEM

JORNADAS DE AUTOMÁTICA (27) (27.2006.ALMERÍA)El objetivo de este trabajo es realizar un modelo dinámico detallado de una pila de combustible tipo PEM de 1.2 kW de potencia nominal. El modelo desarrollado incluye efectos como el ’flooding’ y la dinámica de la temperatura y es de utilidad para poder diseñar y ensayar controles tanto de la válvula de purga como de la refrigeración de la pila mediante un ventilador. Se ha desarrollado un novedoso tratamiento de la ecuación experimental que modela la curva de polarización que simplifica considerablemente su caracterización. Por último el modelo realizado ha sido validado con datos tomados de una pila real

Optimization strategy for element sizing in hybrid power systems

This paper presents a procedure to evaluate the optimal element sizing of hybrid power systems. In order to generalize the problem, this work is based on the “energy hub” concept and formulation previously presented in the literature. The resulting optimization minimizes an objective function based on costs and efficiencies of the system elements, while taking into account the hub model, energy and power constraints and estimated operational conditions, such as energy prices, input power flow availability and output energy demand. The resulting optimal architecture also constitutes a framework for further real–time control designs. Also, an example of a hybrid storage system is considered. In particular, the architecture of a hybrid plant incorporating a wind generator, batteries and intermediate hydrogen storage is optimized, based on real wind data and averaged residential demands. The hydrogen system integrates an electrolyzer, a fuel cell stack and hydrogen tanks. The resulting optimal cost of such hybrid power plant is compared with the equivalent hydrogen–only and battery–only systems, showing improvements in investment costs of almost 30% in the worst case

Control predictivo híbrido de una planta de generación de energía integrando paneles fotovoltaicos y pila de combustible

XXVIII JORNADAS DE AUTOMÁTICA. 05/09/2007. HUELVASe aplican aquí técnicas de control híbrido a una planta de energía conectada a red y que integra paneles solares fotovoltaicos con un sistema secundario de energía formado por electrolizador, tanques de almacenamiento de hidrógeno y pila de combustible. ´ Este sistema, que combina estados tanto continuos como discretos, dado que puede operar en cuatro modos de funcionamiento distintos, es inherentemente híbrido. Así, se obtuvo una descripción MLD Mixed–Logical–Dynamical de la planta, para después diseñar un controlador óptimo basado en técnicas de programación multiparamétricas, adjuntándose también los resultados simulados del comportamiento del controlado

MPC for battery/fuel cell hybrid vehicles including fuel cell dynamics and battery performance improvement

In this paper, the performance and durability of hybrid PEM fuel cell vehicles are investigated. To thatend, a hybrid predictive controller is proposed to improve battery performance and to avoid fuel celland battery degradation. Such controller deals with this complex control problem by handling binaryand continuous variables, piecewise affine models and constraints. Moreover, the control strategy is totrack motor power demand and keep batteries close to a desired battery state of charge which is appro-priately chosen to minimize hydrogen consumption. It is important to highlight the consideration of con-straints which are directly related to the goals of this paper, such as minimum fuel cell power thresholdand time limitation between fuel cell startups and shutdowns. Furthermore, different models have beenelaborated and particularized for a vehicle prototype. These models include few innovations such as a ref-erence governor which smooths fuel cell power demand during sharp power profiles, forcing batteries tosupply such peaks and resulting a longer fuel cell lifetime. Battery thermal dynamics are also taken intoaccount in these models in order to analyze the effect of battery temperature on its degradation. Finally,this paper studies the feasibility of the real implementation, presenting an explicit formulation as a solu-tion to reduce execution time. This explicit controller exhibits the same performance as the hybrid pre-dictive controller does with a reduced computational effort. All the results have been validated in severalsimulation

Estrategia de optimización del tamaño de sistemas híbridos de energía

XXIX JORNADAS DE AUTOMÁTICA ( JA2008) () (29.2008.TARRAGONA. ESPAÑA)Se presenta en este trabajo un metodo sistematizado ´ para la eleccion del tama ´ no˜ optimo de plantas de po- ´ tencia h´ıbridas. En pro de una formulacion general ´ del problema, este estudio se basa en una metodolog´ıa de modelizacion de interfaces de energ ´ ´ıa o “energy hubs” descrita anteriormente en la literatura. La optimizacion resultante minimiza una funci ´ on objetivo ´ basada en costes y eficiencias de los elementos del sistema, teniendose en cuenta asimismo las restricciones ´ presentes y las condiciones de funcionamiento estimadas, leanse precios futuros de la energ ´ ´ıa, disponibilidad de las fuentes y demandas energeticas. La ar- ´ quitectura optima encontrada constituye asimismo un ´ marco para el posterior diseno del controlador del sis- ˜ tema. Usando este planteamiento general, se optimiza el tamano de una instalaci ˜ on consistente en genera- ´ dor eolico, bater ´ ´ıas y almacenamiento intermedio de hidrogeno. Como condiciones de funcionamiento, se ´ usaron datos reales de viento y de demandas residenciales. El sistema de almacenamiento intermedio de hidrogeno integra electrolizador, pila de combustible ´ y tanques de hidrogeno. Comparando la arquitectura ´ h´ıbrida optima con otras distribuciones posibles, se ´ obtienen mejoras en el coste de hasta el 30% con respecto a los casos mas desfavorables

Modelado de un coche híbrido basado en pilas de combustible tipo PEM

XXVIII JORNADAS DE AUTOMÁTICA. 05/09/2007. HuelvaEste artículo presenta el modelo de un coche propulsado por un sistema de potencia híbrido basado en pila de combustible PEM (Polymeric Electrolyte Membrane). El modelo de cada uno de los componentes es cuasi-estático y está orientado para el control de más alto nivel cuyo objetivo es la gestión de potencia entre los distintos elementos. El modelo se realiza después de una fase previa de dimensionado y diseño del sistema en el cual se han seleccionado cada uno de los elementos para que el coche resultante tenga las prestaciones mínimas requeridas a un turismo de circulación