Dr. Liangfei Xu
Associate Professor, Department of Automotive Engineering, Tsinghua University, China

Speech Title: Progress on modelling and control of PEM fuel cell with high efficiency and long lifetime

Abstract: Polymer electrolyte membrane (PEM) fuel cell electric vehicles utilize a PEM fuel cell as the major power source and a battery package as the auxiliary power unit. It has advantages of high efficiency, low noise and zero emission, and is regarded as the future for the electrified transportations. Durability is the key issue for large-scale commercialization of fuel cell vehicles. There are lots of factors that affect the fuel cell durability, and water management is the critical issue. Due to the low operation temperature (less than 100 ℃), there are liquid water, water vapour and membrane water in a fuel cell. How to modelling the water transport behaviour, as well as how to manage the water transport process within a fuel cell stack, become the greatest challenge in this field.

In the past five years, the fuel cell system research group in the State Kay Lab of Automotive Safety and Energy focuses on modeling and control of water transport of PEM fuel cells. A 1D+1D+1D mass transport model for a fuel cell stack is developed. The transient processes of internal states, as well as the hysteristic phenomenen of voltage and water transport, are modeled. A novel test bench for a large active area single cell is developed. Distributed gas concentrations in different channels are sampled and measured, and the results are utilized for validating the model. An online impedance measurement equipment is developed and validated. Internal state algorithms for water content within a stack are developed, and a hierarchical control system that can adjust control targets automatically based on internal states is developed. All these technologies are applied inot a dual recirculation PEM fuel cell system, and the effectiveness of these technologies are verified on test benches.