Low-Cost Electrochemical Impedance Spectroscopy (EIS) Using an Open-Loop DC-DC Converter for Fuel Cells Application

The challenges of diagnosing Fuel Cell (FC) systems are primarily related to the interactions between physical and chemical processes, which are often difficult to detect. The two most used diagnostic techniques in FC systems are the Polarization Curve test and Electrochemical Impedance Spectroscopy (EIS). Both provide valuable information; however, EIS is predominantly applied because it offers more detailed insights into the internal processes of the FC. Nevertheless, it requires expensive equipment, and it is typically limited to a small number of cells in a stack. This paper presents an improved algorithm for obtaining impedance spectroscopy for large FC stacks with a low-cost of implementation, utilizing only a DC/DC converter. Throughout the paper, previously published works are referenced, and the improved algorithm is thoroughly explained. Simulation results, as well as experimental results, are presented, and the main conclusions are drawn.