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This paper presents a 2-D real-time modeling approach for a proton-exchange-membrane fuel cell (PEMFC). The proposed model covers multi-physical domains for both fluidic and electrochemical features, which considers in particular the flow field geometric form of fuel cell. The characteristics of reactant gas convection in the serpentine gas pipeline and diffusion phenomenon through the gas diffusion layer (GDL) are thoroughly considered in fluidic domain model. In addition, a three levels iterative solver is developed in order to accurately calculate the implicit spatial physical quantities distribution in electrochemical domain. Moreover, the proposed 2-D real-time modeling approach uses a numerical method to achieve a fast execution time, and can thus be further easily applied to any real-time control implementation or online diagnostic system. After experimental validation under different fuel cell operating conditions, an iterative Least Angle Regression (LAR) method is used to efficiently and accurately perform the global parameters sensitivity analysis based on Sobol definition. The online analysis results give an insight into the influences of modeling parameters on fuel cell performance. The effect of interactions between parameters’ sensitivities is especially investigated, which can provide useful information for degradation understanding, parameters tuning, re-calibration of the parameters and online prognostic. [ABSTRACT FROM AUTHOR]

As an online adaptive optimization algorithm, the extremum seeking method (ESM) can be effectively employed to find an optimal operating point of a static nonlinear system in real-time. This paper presents a comparative study of different ESM schemes for online energy management strategy of fuel cell hybrid electric vehicles (FCHEVs). By applying the extremum seeking controller, the fuel cell system operating points can be maintained in a high efficiency region and thus saving the hydrogen consumption. In addition, battery state of charge (SOC) is considered as the input of penalty function for extremum seeking controller, in order to prevent over-discharging/over-charging of the lithium-ion battery during the FCHEVs operation. Different schemes of ESM presented in this comparative study consist of first-order ESM, high-pass filter based ESM, and band-pass filter based ESC. The main evaluation criteria in this comparative study include the utilization of lithium-ion battery, the fluctuation of fuel cell system output power, the fuel cell system efficiency and the hydrogen consumption. A Hardware-In-the-Loop (HIL) platform is used to experimentally validate the presented comparative study. Experimental comparison results show that, the performance of all the presented ES controllers is close to that of offline benchmark dynamic programming. The band-pass filter based ES controller is preferred to improve both the performance and durability of energy storage system (ESS) in FCHEVs, since this controller is found to have a good ability to limit the fuel cell power dynamics. [ABSTRACT FROM AUTHOR]

• PDE is used to describe the coupling effects of multi-physical domains in fuel cell. • The PDE-TMET framework achieves rapid prototyping and online implementation. • SSOR increases convergence probability and thus improve calculation efficiency. • The calculation time can be significantly shortened from hours even days to seconds. • MAPE of different physical distribution characteristics can remain within 10%. Fuel cell model provides state observation and quantitative analysis for Hardware-In-the-Loop (HIL) test platform. For a high-dimensional multi-physics model, the observed distribution of physical properties is meaningful for fuel cell stack optimization, manufacturing process and model-based control development. However, traditional modeling approach is difficult to consider both the calculation accuracy and efficiency. To solve this problem, this paper proposes a high-dimensional multi-physics real-time modeling approach for fuel cells based on partial differential equations (PDEs)-tridiagonal matrix equation transformation (TMET) and symmetric successive overrelaxation (SSOR) algorithm. In the proposed method, a generalized framework of TMET and a novel staggered grid technique is developed. In this case, both the convection and diffusion phenomena can be accurately described. For different fuel cells or parameters change, supplementary model modification or development is not required, only the global variables need to be re-assigned. Moreover, SSOR with bi-directional iteration mechanism is used to increase the probability of computational convergence and thus improve the calculation efficiency. Compared with commercial COMSOL model, by using the proposed modeling approach, the mean absolute percentage error (MAPE) of the simulated polarization output characteristics is 1.77%, the MAPE of different distribution characteristics can remain within 10%, and the calculation time can be shortened from hours even days to seconds. [ABSTRACT FROM AUTHOR]