Arafet Bouaicha ¹, Hatem Allagui ¹, El-Hassane Aglzim ², Amar Rouane ³, Adelkader Mami ¹

Affiliations
1 LACS-ENIT/FST Laboratory-Faculty of Sciences of Tunis – El Manar University, Tunis, TN
2 DRIVE Laboratory-University of Bourgogne, Nevers France, FR
3 University of Lorraine, Nancy France, FR

Abstract

Objectives: The objective of this work is the study and validation of the complex impedance measurement system for the PEM fuel cell using STM32F4 microcontroller. We present the technical method for measuring the PEM fuel cell complex impedance using this system. Methods: Among the problems of fuel cells development is still the reliability of their performances over time. The solution of this problem is the implementation of an efficient diagnostic method such as the complex impedance measurement of the cells in order to diagnose it in real time using the Electrochemical Impedance Spectroscopy method (EIS) which is used to diagnose complex electrochemical systems. Findings: To run the complex impedance measurement, it is necessary to use specific software and hardware tools for fuel cells. In this context, we presented the steps of implementation of the system for the measurement of the PEM fuel cell complex impedance. This test bench is realized around the Nexa Ballard PEM fuel cell, an electronic load and a measuring board based on the microcontroller STM32F4 connected to a computer collecting data processed by measurement application developed using LabVIEW® software. The obtained results validate the design of this measuring system. The contribution through the results in this work will be to obtain onboard diagnostic for a PEM fuel cell in the automotive transport field. Application: This system is so small that it can be implemented in an embedded system; it is less expensive than the industrial system for measuring the PEM fuel cell complex impedance.

Keywords

Complex Impedance Measurement, LabVIEW® Applications, PEM Fuel Cell, Real Time Diagnose, STM32F4 Microcontroller.

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Hatem Allagui ¹, Dhia Mzoughi ¹, Arafet Bouaicha ¹, Adelkader Mami ¹

Affiliations
1 Analysis, Conception and Control Systems Laboratory-ENIT, Campus Universitaire - El Manar, Tunis, TN

Abstract

This work concerns the fuel cell systems modeling for their diagnosis. Particularly, we are interested in the systems based on the Nexa 1200W PEM fuel cell. To do this, a dynamic model of this fuel cell taking account of the different physical and chemical phenomena within the stack is presented. It is based principally based on Nerst equation and the use of certain parameters of the Nexa fuel cell provided by the manufacturer. Furthermore, it is accomplished bya certain number of original experimental tests (load modulation method). This model which is designed fortransportation applications contributes to the development offuel cells advanced models because it ensures the decoupling between the different internalphysical phenomena.In fact, to simplify the vehicle motor control, the established model is controlled by an average current at its input. It is especially shown that the membrane of the fuel cell model is solicited by the harmonicsgenerated by the static converters used in the vehicle powertrain powered by the 1.2 kW Nexa fuel cell model. The very important result achieved is that we cantolerate the current harmonics because the double layer capacitor realizes efficient high frequencies harmonic filtering. In this case, the systemstability is noticed. However, the results obtained confirm the use of the Nexa fuel cell system not only in powertrain, but in power electronics generally.

Keywords

Harmonics, Modeling, Nexa, PEM Fuel Cell, Powertrain, Static Converters

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