Comparison of Some Parameter Estimation Techniques Applied to Proton Exchange Membrane Fuel Cell Models

2013 ◽  
Vol 10 (5) ◽  
Author(s):  
Ágnes Havasi ◽  
Róbert Horváth ◽  
Tamás Szabó

The functioning and the achievable power of a proton exchange membrane fuel cell (PEMFC) are determined by several parameters simultaneously. Part of these cannot be measured directly. They must be estimated with parameter fitting techniques. In order to give reliable estimations for the unknown parameters, we first set up an adequate finite difference numerical solution of the mathematical model of the fuel cell. Then the values of the unknown parameters are calculated by fitting the model results to measurements. In this paper our primary aim is to compare several parameter fitting tools on the model of a PEMFC and give a prescription for the use of these methods. We test three methods together with their variants: the Levenberg–Marquardt method, the trust region method, and the simulated annealing method, among which the Levenberg–Marquardt method turns to be the most efficient one.

Author(s):  
Milos Milanovic ◽  
Patrick Rose ◽  
Verica Radisavljevic-Gajic ◽  
Garrett Clayton

In this paper a full nonlinear dynamic control oriented mathematical model of Proton Exchange Membrane (PEM) fuel cell system is developed. The model is structured as a nonlinear five state space model. The derivation of each state equation is based on physics fundamental principles using thermodynamic theory of ideal gas mixtures, conservation of mass law, flow dynamics in serpentine flow channels and diffusion. The output of proposed model, stack voltage, is developed from Nernst equation that includes three main types of losses occurring in the fuel cell. The unknown parameters of the model are estimated and fitted using sets of steady state experimental data. Stack polarization curve of the proposed model is validated by using sets of data for three different values of inlet pressures. Experimental setup used to attain data is the Greenlight Innovation G60 fuel cell test station system and TP50 Fuel Cell stack.


2019 ◽  
Author(s):  
Valentina Guccini ◽  
Annika Carlson ◽  
Shun Yu ◽  
Göran Lindbergh ◽  
Rakel Wreland Lindström ◽  
...  

The performance of thin carboxylated cellulose nanofiber-based (CNF) membranes as proton exchange membranes in fuel cells has been measured in-situ as a function of CNF surface charge density (600 and 1550 µmol g<sup>-1</sup>), counterion (H<sup>+</sup>or Na<sup>+</sup>), membrane thickness and fuel cell relative humidity (RH 55 to 95 %). The structural evolution of the membranes as a function of RH as measured by Small Angle X-ray scattering shows that water channels are formed only above 75 % RH. The amount of absorbed water was shown to depend on the membrane surface charge and counter ions (Na<sup>+</sup>or H<sup>+</sup>). The high affinity of CNF for water and the high aspect ratio of the nanofibers, together with a well-defined and homogenous membrane structure, ensures a proton conductivity exceeding 1 mS cm<sup>-1</sup>at 30 °C between 65 and 95 % RH. This is two orders of magnitude larger than previously reported values for cellulose materials and only one order of magnitude lower than Nafion 212. Moreover, the CNF membranes are characterized by a lower hydrogen crossover than Nafion, despite being ≈ 30 % thinner. Thanks to their environmental compatibility and promising fuel cell performance the CNF membranes should be considered for new generation proton exchange membrane fuel cells.<br>


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