Dynamic flooding management strategy for automotive proton exchange membrane fuel cell system using cathode membrane water content

Abstract

This paper presents a dynamic model for a Proton Exchange Membrane Fuel Cell (PEMFC) system for vehicular applications, focusing on membrane humidity regulation through external humidification and air supply management. The key innovation of this study lies in the introduction of a novel feedback control strategy that uses cathode membrane water content as a control signal, replacing traditional cathode relative humidity (RH) measurements. This approach enables effective management of humidity levels exceeding 100%, ensuring optimal hydration while preventing flooding. The model incorporates key components, including the fuel cell stack, air compressor, humidifier, and bypass valve, to simulate system behavior under varying operating conditions. Results show that increasing current density leads to liquid water accumulation at the cathode, resulting in flooding, while adjusting the bypass valve open ratio significantly affects humidity levels. Lower ratios raise cathode humidity and risk flooding, while higher ratios lead to insufficient membrane hydration. This study’s novel control strategy offers a significant advancement in maintaining cathode relative humidity at 100%, avoiding flooding, and improving overall fuel cell performance in vehicular applications.