Regression analysis of PEM fuel cell transient response

Abstract

To develop operating strategies in polymer electrolyte membrane (PEM) fuel cell-powered applications, precise computationally efficient models of the fuel cell stack voltage are required. Models are needed for all operating conditions, including transients. In this work, transient evolutions of voltage, in response to load changes, are modeled with a sum of three exponential decay functions. Amplitude factors are correlated to steady-state operating data (temperature, humidity, average current, resistance, and voltage). The obtained time constants reflect known processes of the membrane heat/water transport. These model parameters can form the basis for the prediction of voltage overshoot/undershoot used in computational-based control systems, used in real-time simulation. Furthermore, the results provide an empirical basis for the estimation of the magnitude of temporary voltage loss to be expected with sudden load changes, as well as a systematic method for the analysis of experimental data. Its applicability is currently limited to thin membranes with low to moderate humidity gases, and with adequately high reactant-gas stoichiometry.

New Equivalent Electrical Model of a Fuel Cell and Comparative Study of Several Existing Models with Experimental Data from the PEMFC Nexa 1200 W

“…Using the simulation RC model shown in Figure 4, the shape of the transient response of this model to the step load change is represented in Figure 5. It should be noted that when the load current steps up, the voltage drops simultaneously to some value due to the ohmic losses, and then it decays exponentially to its steady-state value due to the capacitor C. However, the experimental voltage of the PEMFC, as can be seen later (Section 5) and found in many works [12,31,32] has the form of Figure 5. This figure clearly illustrates a big difference between the experimental fuel cell voltage and the corresponding voltage given by the RC model.…”

Modified Variable DC Approach Applicable to Fuel Cells and DOL Batteries in Shipboard Power Systems

“…The system must be designed such that the DC bus voltage and battery SOC stay within their allowed operation ranges. Additionally, since FCs are typically very sensible to quick power transients [15], the FCs must be prevented from experiencing quick power transients. A load power transient is considered quick if it leads to FC current increasing or…”

Prediction of Power Characteristic Curve on Small Scale Compressed Air Energy Storage by Using Regression Analysis

“…By using this technique, the relationship between variables that enter the regression process will be found without needing to enter the coefficient and constants needed in mathematical techniques. Thus, it will make it easier to know the power curve by ignoring these values [35]- [37].…”

“…In other studies, there have been several studies that discussed the use of polynomial regression, to be able to predict the characteristics of data. Some of the studies included [37] used polynomial regression to analyze transient responses from PEM fuel cells. In other research carried out by Fumo et al [38], this regression technique was used to predict the energy consumption in residential buildings.…”