Research on a Current-Controlled Voltage Regulation Digital System for Online Electrochemical Impedance Spectroscopy of Space Fuel Cells

With the escalating demand for high-performance energy systems in spacecraft, Proton Exchange Membrane Fuel Cells (PEMFCs), characterized by their high power density and longevity, have emerged as a preferred option for space applications. Electrochemical Impedance Spectroscopy (EIS) stands as a potent diagnostic tool for PEMFC malfunctions; however, conventional EIS measurements necessitate equipment such as electrochemical workstations, inhibiting their integration into spatial PEMFC systems. Addressing this challenge, this study devises a strategy that integrates the EIS measurement system with the DC/DC converter at the output end of space PEMFCs. A current-controlled voltage regulation method for online EIS measurements is proposed, employing a dual closed-loop control strategy to ensure the stability of the PEMFC output voltage during EIS assessments, thereby fulfilling the stringent stability requirements of operating voltages in space applications. The successful development and validation of a digital system for in-situ EIS measurements in PEMFCs not only underpin robust fault diagnostics for space fuel cells but also facilitate advancements in the stability and durability of PEMFC systems, thereby positively contributing to the progression of aerospace energy technologies.