Analysis of PEMFC undershoot behavior and performance stabilization under transient loading

Abstract

A global full state model considering both steady and dynamic performance of proton exchange membrane fuel cell (PEMFC) is developed to analyze the voltage undershoot behavior and performance stabilization under transient loading. The research investigates the underlying causation of operating conditions, reactant starvation level and control strategy of undershoot behavior. Experiments are conducted to obtain data for calibrating the model. The voltage undershoot principles and the alleviation method are investigated. The results show that the model deviations are limited within 2% relative errors. The voltage undershoots and voltage delay-time recovery under transient loading could be accurately characterized by exploring the internal substance transport and heat transfer. The voltage undershoot amplitudes are mainly influenced by the reactant concentration ratio of consumption part to initial part before loading in membrane electrode assembly. Moreover, the performance stabilization methods can be developed for loading boundary definition and operating parameter adjustment. The study is significant to provide a guidance for the enhancement of PEMFC performance stability.