D17.2 - Real Time Converter-Based EIS with Output Disturbance Mitigation for Fuel Cell Application

Electrochemical Impedance Spectroscopy (EIS) is a fundamental tool in Fuel Cell (FC) diagnostics. It provides information on both electrical and electrochemical behaviors, by measuring the equivalent impedance. Converterbased EIS has gained significant attention due to its practicality and integration potential. However, such methods are limited in real-time applications because the injected perturbations propagate to the system output, causing undesirable AC ripple that have a negative effect on the connected load. To address this challenge, this paper presents a closed-loop converter-based EIS that mitigates the AC ripple using a resonant controller in combination with a frequency customized lead filter. The proposed method enables accurate impedance measurements without compromising the output voltage stability. Both simulation and experimental results are presented, and the main conclusion are drawn.