A Comparative Study of Using Polarization Curve Models in Proton Exchange Membrane Fuel Cell Degradation Analysis

In this paper, a systematic study is carried out to compare the performance of various V-I models at both normal and faulty conditions, in terms of simulating proton exchange membrane fuel cell (PEMFC) behavior and analyzing the corresponding degradation process. In the analysis, the simulation accuracy of V-I models, including overall behavior simulation and the simulation of different PEMFC losses, is investigated. Results show that compared to the other V-I models, the V-I model using exponential function for mass transport loss and considering open circuit voltage (OCV) at zero current can provide the best simulation performance, with an overall root mean square error (RMSE) of about 0.00279. Furthermore, the performance of these V-I models in analyzing PEMFC degradation process is also studied. By investigating the evolution of PEMFC losses during the degradation, the effectiveness of these models in interpreting PEMFC degradation mechanisms can be clarified. The results show that, besides the simulation accuracy, different interpretations may be provided from different models; this further confirms the necessity of comparative study. Moreover, the effectiveness of different V-I models in identifying PEMFC abnormal performance at two faulty scenarios is investigated. The results demonstrate that, among different V-I models, the model using an exponential function for mass transport loss and considering OCV at zero current can provide more accurate simulation and reasonable interpretation regarding PEMFC internal behavior.