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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 the modeling approach for a quasi-2-D tubular anode-supported solid-oxide fuel cell (SOFC) for real-time control implementation. The proposed system considers a multidomain electrochemical, fluidic, and thermal dynamic modeling and it is experimentally validated against a SOFC real world implementation. Implicit iterative algebraic equations have been introduced and implemented in C language in order to have fast real-time execution. The methodology for implementing such an iterative solver is discussed in details and the results demonstrate practical feasibilities in advancing real-time control of SOFC [ABSTRACT FROM AUTHOR]

Power electronic converters are essential part of hybrid fuel cell automotive application systems. The converter needs to provide high-voltage ratio for a wide range of input voltage. In addition, the converter should have high efficiency for a wide range of duty cycle control range. A four-phase floating interleaved boost converter (FIBC) is analysed and a small-signal AC model using an averaged pulse-width modulation (PWM) switch technique is used for supporting the feedback controller and aiding a frequency response design. The small-signal AC model as well as the current controller are validated by simulation and evaluated by experimental results. The proposed converter has competitive device ratings, the total inductance volume and weight is decreased, current ripple is minimised and converter efficiency and reliability are improved. Proof of concept of the proposed topology is demonstrated through an experimental prototype. [ABSTRACT FROM AUTHOR]

Electric vehicle technology has been adopting fuel cells (FCs) for hybrid applications over the past few years. Therefore, the development of advanced power electronic systems for the integration of fuel cells with on-board energy management is fundamental for achieving high-performance systems. An FC for vehicular applications is usually a low-voltage current-source like device that produces electricity and heat directly from input hydrogen and oxygen. Most often, it is required that the FCs be stacked for high-voltage dc-link in order to supply the input power for the drivetrain and electric motor drive system. The FC has a nonlinear nature, and it must be controlled to operate in the high-efficiency operating range. Hybrid electric vehicles have physical constraints such as volume and weight under limited cost and expected lifetime. There is a need for high-voltage input/output ratio of dc-dc boost converters to be connected between the FC to the motor drive dc-link. In addition, it is necessary to have low input ripple at the dc-dc boost converter in order to maximize the FC lifetime, and the traditional dc-dc boost converter topologies have poor performance on these specifications. This paper proposes a new dc-dc converter family of topologies aimed at improving the application to electric vehicle power control. This family is defined as floating-interleaving boost converters (FIBCs). The paper will thoroughly show analysis and experimental verification of FIBC's, and they will be compared with conventional boost converter characteristics. The paper supports how performance figures related to the passive components, i.e., the inductor and capacitor, will have better volume and weight, extremely low input current ripple, and improved efficiency and transfer ratio. The analysis presented in this paper shows how to choose the most suitable topology in order to achieve the desired specifications. The selected topology is fully validated experimentally using advanced nonlinear sliding mode control, which has the additional feature of operating even in faulty conditions. [ABSTRACT FROM PUBLISHER]

This paper describes two different control strategies for a fuel-cell-based hybrid electric vehicle (FCHEV). The offline strategy is based on dynamic programming, and the online strategy is based on an optimized fuzzy logic controller. These two strategies are then compared. Finally, the fuzzy logic controller is validated using a real FCHEV. [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]

This paper describes a new methodology based on the statistical description of driving cycles to size the energy source of a hybrid vehicle. This methodology is applied to a fuel-cell-based collection truck for very specific driving patterns. Based on experimental data, random driving cycles are then generated, allowing the distribution of the average powers and energies to be computed. The analysis proves that a 20-kW fuel cell stack is sufficient for a 13 000-kg truck. The results show that the fuel cell system could be downsized, compared with classical solutions, where much larger fuel cells are required. [ABSTRACT FROM PUBLISHER]

In this paper, a multiphysical proton exchange membrane fuel cell stack model, which is suitable for real-time emulation is presented. The model covers three physical domains: electrical, fluidic, and thermal. A Ballard 1.2 kW 47 cells fuel cell stack model is introduced. The corresponding fuel cell system auxiliary models are given based on experimental tests. Based on the modeling equations, the fuel cell dynamic phenomena in different physical domains are analyzed and the corresponding time constant expressions are given. Using the real-time stack model, a fuel cell stack emulator based on a buck converter is used to emulate the fuel cell stack electrical part. The experimental results show that the emulator can reproduce the real-stack behavior with a great agreement. Such a fuel cell stack emulator can be used for hardware-in-the-loop applications, in order to test and validate the fuel cell system design. [ABSTRACT FROM PUBLISHER]

This paper describes the design of a high-speed three-phase switched reluctance machine to drive a compressor for the air management of a fuel-cell system for automotive applications. The machine geometry is optimized by means of a finite-element method coupled to a genetic algorithm. The performance of the optimized machine is evaluated, taking into account the iron and air-friction losses. Some theoretical and numerical results are sustained by the measured ones in the same operating conditions. [ABSTRACT FROM AUTHOR]

This paper presents cell-layer-scale multidomain dynamic 1-D proton-exchange-membrane fuel-cell (PEMFC) stack model using VHDL-AMS modeling language. The model covers three main fuel-cell energy domains: electrical, fluidic, and thermal. The performance and advantages of the VHDL-AMS language are shown in the first part. Then, by means of the "top-down" modeling approach, the electrical-, fluidic-, and thermal-domain models of the PEMFC stack are addressed in three separate parts. Simulation results are then compared with a Ballard 1.2-kW NEXA fuel-cell system and show a great agreement with experimental data. This complex multidomain VHDL-AMS stack model, containing more than 25 000 state variables and only few empirical coefficients (four parameters identified on the polarization curve), can be used for fuel-cell system components design and also for real-time applications. Real-time simulation is a key issue in many applications such as system control and hardware-in-the-loop applications. Moreover, this fuel-cell stack model is suitable and can be parameterized for all kinds of PEMFC including water-cooled and metal bipolar plates stacks: Only the cooling fluid and materials properties have to be changed. [ABSTRACT FROM AUTHOR]

This paper presents a hardware-in-the-loop experimental rig for testing a proton exchange membrane fuel cell (PEMFC) driving an electrical vehicle. The PEMFC includes an air-management system with a scroll compressor driven by a high- performance sensorless induction motor drive. The sensorless technique is based on a neural-network-based speed observer, i.e., the total least-squares EXIN full-order observer. The whole system is driven by a classic European Driving Cycle (EEC Directive 90/C81/01). An experimental rig has been built to test the system. The torque-speed characteristics of a real scroll compressor have first been measured. Then, these characteristics have been emulated by a brushless interior-mounted permanent-magnet machine controlled in torque. This emulated scroll compressor has been driven by a sensorless field-oriented controlled induction motor drive. The experimental results show that the system attains a global efficiency of about 50% and that the speed estimation accuracy is high at both very low and very high speeds with a stable behavior at zero speed at no load, which is particularly difficult to achieve for model-based sensorless techniques. [ABSTRACT FROM AUTHOR]

This paper proposes a technological solution with a scroll compressor driven by a high-performance induction machine drive for the air management of proton exchange membrane fuel cells (PEMFC) for automotive applications. The torque-speed characteristics of a real scroll compressor have been measured and then emulated by a brushless internal mounted permanent magnets machine controlled in torque. This emulated scroll compressor has been driven by a field-oriented controlled induction motor drive. The whole car model as well as the PEMFC have been implemented by software on the same DSP which implements the drive control algorithm; in this way, the hardware-in-the-loop structure has been employed for emulating the behavior of a real car including the electrical supply of the PEMFC. The whole system has been tested with a classic European Driving Cycle. Two experimental rigs have been setup, one for characterizing the scroll compressor and the other for emulating the entire vehicle. The experimental results have shown that the speed reference profile, obtained during a urban driving cycle, is followed correctly, and that the tank-to-wheel efficiency remains at quite high values confirming the goodness of the proposed technological solution. The hardware-in-the-loop approach of the experimental rig allows tests to be performed to verify the operation in steady and transient states with low cost and reduced employment of the fuel cell stack, with resulting increased durability. [ABSTRACT FROM AUTHOR]