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Papers by Angel Urquia
Journal of Power Sources, 2008
A novel methodology for the diagnosis of an operating proton exchange membrane fuel cell (PEMFC) ... more A novel methodology for the diagnosis of an operating proton exchange membrane fuel cell (PEMFC) is proposed in this manuscript. The cell impedance can be represented as the sum of two terms: the membrane resistance and a second-order transfer function. An experimental procedure and a method to estimate the parameters of this impedance model from the experimental data, by applying parameter identification techniques, are proposed. The experimental procedure consists in reading the dynamic response of the cell voltage and current after the occurrence of small changes in the load value. This experimental procedure, intended for application on operating cells, does not significantly interfere with the cell operation. It has been designed supposing that the frequency range of the relevant cell phenomena is 1 Hz to 5 kHz. The required experimental equipment is inexpensive and easily portable. Analytical relationships have been derived in order to calculate the following cell electrochemical parameters from the model parameters: the diffusion resistance, the charge transfer resistance, the diffusion-related time constant, the membrane resistance and the double layer capacitance.
International Journal of Hydrogen Energy, 2010
Impedance spectroscopy Electrochemical parameters CO poisoning Flooding Membrane drying a b s t r... more Impedance spectroscopy Electrochemical parameters CO poisoning Flooding Membrane drying a b s t r a c t A novel diagnosis methodology for characterizing the cathode flooding, the membrane drying and the anode catalyst poisoning by carbon monoxide is proposed in this manuscript. This diagnosis methodology is intended to be used in portable control systems. Two equivalent-circuit models for PEM fuel cells (PEMFC) with a low computational cost are proposed. The first model describes the dynamic behavior of the PEMFC during its normal operation, and also during the cathode flooding and the membrane drying processes. A method to estimate the parameters of this model is proposed. The experimental procedure for data acquisition does not interfere significatively with the cell operation, and the measurement equipment is easily portable and inexpensive. The second model reproduces the cell dynamic behavior when the anode catalyst is poisoned by carbon monoxide. The relationship among the parameters of these equivalent-circuit models and PEMFC electrochemical parameters is stated. (M.A. Rubio), aurquia@dia.uned.es (A. Urquia), sdormido@dia.uned.es (S. Dormido). A v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / h e
Journal of Power Sources, 2007
Electrochemical Impedance Spectroscopy (EIS) is widely used for the characterization of PEM fuel ... more Electrochemical Impedance Spectroscopy (EIS) is widely used for the characterization of PEM fuel cells. In particular, EIS data is used for parameter estimation of the PEMFC equivalent circuit model. However, EIS exhibits some practical limitations when it is applied to the in-field diagnosis and control of fuel cells (e.g., the equipment's size, weight and cost). An alternative methodology for the parameter estimation of the PEMFC equivalent circuit is proposed. Firstly, the cell's transient response after current interruption is experimentally measured. The equipment required to perform this experiment is easily portable and inexpensive. Secondly, the cell equivalent circuit parameters are estimated by fitting the cell's experimental data to the analytical expression of the cell model transient response after current interruption. The application of this cell assessment methodology is illustrated by means of a case study: the diagnosis of the cathode flooding in a PEM fuel cell.
Journal of Power Sources, 2008
A novel methodology for the diagnosis of an operating proton exchange membrane fuel cell (PEMFC) ... more A novel methodology for the diagnosis of an operating proton exchange membrane fuel cell (PEMFC) is proposed in this manuscript. The cell impedance can be represented as the sum of two terms: the membrane resistance and a second-order transfer function. An experimental procedure and a method to estimate the parameters of this impedance model from the experimental data, by applying parameter identification techniques, are proposed. The experimental procedure consists in reading the dynamic response of the cell voltage and current after the occurrence of small changes in the load value. This experimental procedure, intended for application on operating cells, does not significantly interfere with the cell operation. It has been designed supposing that the frequency range of the relevant cell phenomena is 1 Hz to 5 kHz. The required experimental equipment is inexpensive and easily portable. Analytical relationships have been derived in order to calculate the following cell electrochemical parameters from the model parameters: the diffusion resistance, the charge transfer resistance, the diffusion-related time constant, the membrane resistance and the double layer capacitance.
International Journal of Hydrogen Energy, 2010
Impedance spectroscopy Electrochemical parameters CO poisoning Flooding Membrane drying a b s t r... more Impedance spectroscopy Electrochemical parameters CO poisoning Flooding Membrane drying a b s t r a c t A novel diagnosis methodology for characterizing the cathode flooding, the membrane drying and the anode catalyst poisoning by carbon monoxide is proposed in this manuscript. This diagnosis methodology is intended to be used in portable control systems. Two equivalent-circuit models for PEM fuel cells (PEMFC) with a low computational cost are proposed. The first model describes the dynamic behavior of the PEMFC during its normal operation, and also during the cathode flooding and the membrane drying processes. A method to estimate the parameters of this model is proposed. The experimental procedure for data acquisition does not interfere significatively with the cell operation, and the measurement equipment is easily portable and inexpensive. The second model reproduces the cell dynamic behavior when the anode catalyst is poisoned by carbon monoxide. The relationship among the parameters of these equivalent-circuit models and PEMFC electrochemical parameters is stated. (M.A. Rubio), aurquia@dia.uned.es (A. Urquia), sdormido@dia.uned.es (S. Dormido). A v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / h e
Journal of Power Sources, 2007
Electrochemical Impedance Spectroscopy (EIS) is widely used for the characterization of PEM fuel ... more Electrochemical Impedance Spectroscopy (EIS) is widely used for the characterization of PEM fuel cells. In particular, EIS data is used for parameter estimation of the PEMFC equivalent circuit model. However, EIS exhibits some practical limitations when it is applied to the in-field diagnosis and control of fuel cells (e.g., the equipment's size, weight and cost). An alternative methodology for the parameter estimation of the PEMFC equivalent circuit is proposed. Firstly, the cell's transient response after current interruption is experimentally measured. The equipment required to perform this experiment is easily portable and inexpensive. Secondly, the cell equivalent circuit parameters are estimated by fitting the cell's experimental data to the analytical expression of the cell model transient response after current interruption. The application of this cell assessment methodology is illustrated by means of a case study: the diagnosis of the cathode flooding in a PEM fuel cell.