Inverter ripple as a diagnostic tool for ohmic resistance measurements on PEM fuel cells

This paper reapproaches the possibility to use the current ripple introduced by power conditioning devices on fuel cells for a low-cost monitoring of the cell ohmic resistance, suitable for commercial applications. Being the ohmic resistance strongly dependent on the membrane water content, this technique can be usefully employed as a diagnostic tool for membrane humidity control. The proposed method is tested on a single PEM fuel cell with a simulated inverter ripple. The fuel cell response is analyzed in the frequency domain to improve the ohmic resistance estimate by fitting impedance values at different frequencies.