AUTHORS: Marc Schumann, Florian Grumm, Jan Friedrich, Detlef Schulz

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ABSTRACT: Common controlling strategies of fuel cells regulate parameters like the flow rates, pressures, temperatures, and relative humidities of the supplied gases. These strategies have a slow control effect on the fuel cell output voltage, especially at high dynamic loads, which is why fuel cell voltage and power drops for several seconds to minutes after a load step. Today, an oversizing of fuel cell systems is necessary to meet the requirements of dynamic load profiles. This paper deals with the design and implementation of an electric field modifier (EFM) control unit into fuel cells to enable the regulation of an additional control parameter, which is considerably faster than the common parameters. The EFM control unit consists of EFM electrodes that are placed directly on or in the membrane of polymer exchange membrane fuel cells and are connected to an external controllable voltage source. Possible electrical connections and actuating signals are presented. Deduced advantages include a better dynamic fuel cell system voltage behavior, a cost- and weight-optimized on-board grid integration, and a prolonged membrane durability.

KEYWORDS: electric field modifier design, electric field modifier implementation, electrically controllable membrane electrode assembly, dynamic behavior, electrical connection, actuating signals

REFERENCES:

[1] J. Cho, H.-S. Kim, K. Min, Transient response of a unit proton-exchange membrane fuel cell under various operating conditions, Journal of Power Sources, Vol. 185, 2008, pp. 118-128.

[2] H.-S. Kim, K. Min, Experimental investigation of dynamic responses of a transparent PEM fuel cell to step changes in cell current density with operating temperature, Journal of Mechanical Science and Technology, Vol. 22, 2008, pp. 2274-2285.

[3] Q. Yan, H. Toghiani, H. Causey, Steady state and dynamic performance of proton exchange membrane fuel cells (PEMFCs) under various operating conditions and load changes, Journal of Power Sources, Vol. 161, 2006, pp. 492-502.

[4] H. Weydahl, Dynamic behaviour of fuel cells, Ph.D. dissertation, Norwegian University of Science and Technology, Trondheim, 2006. Accessed on: February 25, 2019.

[Online]. Available: https://brage.bibsys.no/xmlui/handle/11250/248 695

[5] W. R. W. Daud, R. E. Rosli, E. H. Majlan, S. A. A. Hamid, R. Mohamed, T. Husaini, PEM fuel cell system control: A review, Renewable Energy, Vol. 113, 2017, pp. 620-638.

[6] A. Lücken, T. Kut, M. Terörde, S. Dickmann, D. Schulz, Integration Scenarios to Improve Fuel Cell Dynamics for Modern Aircraft Application, IEEE 48th Universities’ Power Engineering Conference UPEC 2013, Dublin, Ireland, Sep. 2-6, 2013. Fig. 7. New simple power electronics subsystem with an electric field modifier (EFM) control unit, own representation and extension according to

[17]: reactant flow rate d𝑚𝑚/d𝑡𝑡, reactant partial pressures 𝑝𝑝, reactant relative humidity 𝜑𝜑, operating temperature 𝑇𝑇, fuel cell voltage 𝑣𝑣, fuel cell current 𝑖𝑖, and internal controlling voltage 𝑣𝑣e−control . WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS Marc Schumann, Florian Grumm, Jan Friedrich, Detlef Schulz E-ISSN: 2224-266X 61 Volume 18, 2019

[7] J. A. Oliver et al, High level decision methodology for the selection of a fuel cell based power distribution architecture for an aircraft application, 2009 IEEE Energy Conversion Congress and Exposition, San Jose, CA, 2009, pp. 459-464.

[8] F. Grumm, M. F. Meyer, A. Lücken, J. Storjohann, D. Schulz, M. Schumann, Robust Primary Protection Device for weightoptimized PEM Fuel Cell Systems in High Voltage DC Power Systems of Aircraft, IEEE Trans. Ind. Electron., Vol. 66, 2019, pp. 5748- 5758.

[9] P. Kurzweil, Fuel Cell Technology, (in German: Brennstoffzellentechnik), 2nd ed., Springer Vieweg, Wiesbaden, 2013, p. 79.

[10] J. Jia, Q. Li, Y. Wang, Y. T. Cham, M. Han, Modeling and Dynamic Characteristic Simulation of a Proton Exchange Membrane Fuel Cell, IEEE Transactions on Energy Conversion, Vol. 24, 2009, pp. 283-291.

[11] R. O’Hayre, S.-W. Cha, W. Colella, F. B. Prinz, Fuel Cell Fundamentals, 2nd ed., John Wiley & Sons, New York, 2008, pp. 147-154.

[12] D. Schulz, Fuel cell membrane unit, controllable fuel cell and high pressure electrolytic cell, (in German: Brennstoffzellenmembraneinheit, steuerbare Brennstoffzelle und Hochdruckelektrolysezelle), German patent DE102011088613B3, Publication Date: 12/06/2012.

[13] D. Schulz, Internally controllable fuel cell, European patent, Patent No.: EP2791392B1, Publication Date: Aug. 16, 2017.

[14] D. Schulz, Internally controllable fuel cell, United States patent, Patent No.: US9437887B2, Publication Date: Sep. 6, 2016.

[15] D. Schulz, Internally controllable fuel cell, Chinese patent, Patent No.: CN104093885B, Publication Date: Dec. 4, 2017.

[16] S. P. Balomenou, F. Sapountzi, D. Presvytes, M. Tsampas, C. G. Vayenas, Triode fuel cells, Solid State Ionics, Vol. 177, 2006, pp. 2023- 2027

[17] F. Barbir, PEM Fuel Cells Theory and Practice, 2nd ed., Elsevier/Academic Press, Amsterdam/Boston, 2013.