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This paper proposes a control technology of an ultrahigh-speed centrifugal compressor for the air management of proton exchange membrane fuel cells for automotive applications. The mathematical model of the air management system (AMS) is experimentally validated. The implementation of a fast butterfly valve with a proportional–integral controller overcomes the difficulty of pressure ratio control, to make the system work on the optimal operating points. The application of a reference limiter restricts the trajectory of the operating points in the right region of the surge line to ensure the safety of the compressor. Experimental results show the goodness of the reference tracking property, in terms of mass flow and pressure. Meanwhile, the surge phenomenon is prevented by the reference limiter. [ABSTRACT FROM PUBLISHER]

This paper presents a multiphysical proton exchange membrane fuel cell (PEMFC) stack model. The stack model is divided into three submodels describing the different physical domains, namely, electrical, fluidic, and thermal. The stacking method has been used to model the fuel cell stack from a single-cell model. The proposed model has been validated against a 1.2-kW commercial PEMFC stack with excellent agreement between simulation and experimentation. Based on the simulation results, a novel model reduction method is proposed. The reduced model is suitable for real-time simulation purpose. Moreover, a real-time-model-based fuel cell emulator is introduced. The emulator has three real-time computation cores with different rates. The three computation cores are interconnected with a digital communication bus. A dc/dc buck converter is designed in order to receive the model-predicted stack power conditions and emulate the real fuel cell stack power output. The experimental test results show that such an emulator is suitable for fuel cell system hardware-in-the-loop applications. [ABSTRACT FROM AUTHOR]

Abstract: A generalized, cell layer scale proton exchange membrane fuel cell (PEMFC) stack dynamic model is presented using VHDL-AMS (IEEE standard Very High Speed Integrated Circuit Hardware Description Language-Analog and Mixed-Signal Extensions) modeling language. A PEMFC stack system is a complex energy conversion system that covers three main energy domains: electrical, fluidic and thermal. The first part of this work shows the performance and the advantages of VHDL-AMS language when modeling such a complex system. Then, using the VHDL-AMS modeling standards, an electrical domain model, a fluidic domain model and a thermal domain model of the PEMFC stack are coupled and presented together. Thus, a complete coupled multi-domain fuel cell stack 1-D dynamic model is given. The simulation results are then compared with a Ballard 1.2kW NEXA fuel cell system, and show a great agreement between the simulation and experimentation. This complex multi-domain VHDL-AMS stack model can be used for a model based control design or a Hardware-In-the-Loop application. [Copyright &y& Elsevier]

Abstract: The use of hydrocarbon fed fuel cell systems including a fuel processor can be an entry market for this emerging technology avoiding the problem of hydrogen infrastructure. This article presents a 1 kW low temperature PEM fuel cell system with fuel processor, the system is fueled by a mixture of methanol and water that is converted into hydrogen rich gas using a steam reformer. A complete system model including a fluidic fuel processor model containing evaporation, steam reformer, hydrogen filter, combustion, as well as a multi-domain fuel cell model is introduced. Experiments are performed with an IDATECH FCS1200™ fuel cell system. The results of modeling and experimentation show good results, namely with regard to fuel cell current and voltage as well as hydrogen production and pressure. The system is auto sufficient and shows an efficiency of 25.12%. The presented work is a step towards a complete system model, needed to develop a well adapted system control assuring optimized system efficiency. [Copyright &y& Elsevier]