Dither-less extremum seeking for hydrogen minimization in PEM fuel cells

This paper presents a nonsmooth adaptive extremum seeker that minimizes the hydrogen consumption in a fuel-cell system. The extremum seeker operates by estimating the gradient of the objective function but, unlike other seekers, it does not require a dither signal to produce such estimate. The absence of a dither signal simplifies the choice of parameter values for the seeker, and more importantly, it allows it to converge to the optimal value exactly, not only to a small neighborhood. The proper functioning of the proposed scheme is proved using nonsmooth Lyapunov analysis. The strategy is tested on the input-output map of a real polymer electrolyte fuel cell.The research of C. Kunusch has been supported by the Seventh Framework Programme of the European Community through the Marie Curie actions (GA: PCIG09-GA-2011-293876), the Puma-Mind project (GA: FCH-JU-2011-1-303419), the CICYT project DPI2011-25649 (MINECO-Spain), the CSIC MACPERCON project (201250E027) and the CSIC JAE-DOC Research Programme.Peer Reviewe

On the implementation of an adaptive extremum seeking algorithm for hydrogen minimization in PEM fuel cell based systems

This work presents initial experimental results of an adaptive sliding-mode extremum seeker that minimizes the hydrogen consumption in a fuel cell based system. The extremum seeker is based on the classical steepest-descent method, the main challenge being the fact that the gradient of the objective function is unknown. The gradient is estimated by means of a sliding-mode adaptive estimator. The strategy is applied in experimental practical situations in a fuel cell test bench, this allows to asses the performance of the scheme as well as the difficulties that arise in real applicationsPeer ReviewedPostprint (author’s final draft

On the implementation of an adaptive extremum seeking algorithm for hydrogen minimization in PEM fuel cell based systems

This work presents initial experimental results of an adaptive sliding-mode extremum seeker that minimizes the hydrogen consumption in a fuel cell based system. The extremum seeker is based on the classical steepest-descent method, the main challenge being the fact that the gradient of the objective function is unknown. The gradient is estimated by means of a sliding-mode adaptive estimator. The strategy is applied in experimental practical situations in a fuel cell test bench, this allows to asses the performance of the scheme as well as the difficulties that arise in real applicationsPeer ReviewedPostprint (author’s final draft

Control-oriented model of a membrane humidifier for fuel cell applications

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Improving the humidification of polymer electrolyte membrane fuel-cells (PEMFC) is essential to optimize its performance and stability. Therefore, this paper presents an experimentally validated model of a low temperature PEMFC cathode humidifier for control/observation design purposes. A multi-input/multi-output non-linear fourth order model is derived, based on the mass and heat dynamics of circulating air. In order to validate the proposed model and methodology, experimental results are provided. Finally, a non-linear control strategy based on second order sliding mode is designed and analyzed in order to show suitability and usefulness of the approach.Peer ReviewedPostprint (author's final draft

Identification and observation in the anode line of PEM fuel cell stacks

In this work, some potential identification/observation problems that arise in the anode line of a typical Polymer Electrolyte Membrane (PEM) fuel cell based system are highlighted and then solved. They involve estimating the hydrogen input flow at the stack anode and the water transport across the membrane. It is argued that estimating the membrane water transport is of special interest since it gives relevant information on the actual performance and state of the fuel cell. Both problems are solved by constructing robust observers and parameter identification algorithms based on the Generalized Super-Twisting Algorithm.Peer ReviewedPostprint (author’s final draft

Optimization-based thermal control strategy for auxiliary cooling circuits in fuel cell vehicles

© 2022 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 worksIn this research work, a thermal management concept for the auxiliary components in fuel cell vehicles is discussed. A control-oriented model of the subsystem under analysis is developed and then used as basis for controller development. Two control strategies are implemented and compared. The first is a PI-controller strategy and it is used as a baseline for performance comparison. The second is an optimization-based controller (OBC) strategy focused on minimizing the power consumption of the main actuator. The OBC features a novel steady-state observer (SSO) developed for thermal circuits and provides an estimation of the steady-state conditions and conveniently simplifies the optimization problem by disregarding the dynamics of the states so that it can be implemented online with lower computational burden. Comparisons between PI-control strategy and OBC demonstrate the OBC’s capabilities in overcoming typical problems associated with the PI-control strategy including high power consumption of the actuators and temperature constraint violations under particular operating conditions.Postprint (author's final draft

Control of an active rectifier with an inductive-capacitive-inductive filter using a Twisting based algorithm

This paper presents a novel controller for an active rectifier with an inductive-capacitive-inductive filter. The proposed control scheme comprises two levels. The internal level, is a current controller based on the second order sliding mode Twisting algorithm, which robustly ensures an unity power factor at the connection point. The slower external level is a PI controller in charge of regulating the output DC voltage to a desired reference. The controller setup also includes a finite-time observer of the current derivative that can be used to avoid direct (and sometimes problematic) numerical differentiation. Finally, simulation results are presented to validate the proposed control scheme.Instituto de Investigaciones en Electrónica, Control y Procesamiento de SeñalesConsejo Nacional de Investigaciones Científicas y Técnica

Modeling, diagnosis and control of fuel-cell-based technologies and their integration in smart-grids and automotive systems

The main objective of the current Special Section is to collect, formally present and discuss the most recent and relevant advances in control-oriented modeling and validation, system diagnosis and advanced control design of complex energy conversion systems based on fuel cells. Moreover, the Special Section is also focused on providing the researchers and engineers with the state-of-art research and guidelines in these important fields for the next years. In total, the Special Session is composed by 17 contributions covering the research in theoretical aspects related to modelling, diagnosis and control applied to energy management systems based on fuel cells or considering fuel cells as part of overall hybrid systems.Peer ReviewedPostprint (author's final draft

Efficiency Optimisation of an Experimental PEM Fuel Cell System via Super Twisting Control

A robust control solution is proposed to solve the air supply control problem in autonomous polymer electrolyte membrane fuel cells (PEMFC) based systems. Different second order sliding mode (SOSM) controllers are designed using a model of a laboratory test fuel cell generation system. Very good simulation results are obtained using such algorithms, showing the suitability of the SOSM approach to PEMFC stack breathing control. Subsequently, for experimental validation, a controller based on one of the previously assessed SOSM algorithms, namely a Super Twisting, is successfully implemented in the laboratory test bench. Highly satisfactory results are obtained, regarding dynamic behaviour, regulation error and robustness to uncertainties and external disturbances.Instituto de Investigaciones en Electrónica, Control y Procesamiento de Señale