Feedback linearization control of the air supply system of PEM fuel cells

The air supply system, providing oxygen for the fuel cell stack, is one of the most important subsystems of a typical proton exchange membrane fuel cell (PEMFC) system. In this paper, a feedback linearization controller is proposed to control the air mass flow rate to avoid the oxygen starvation and reduce energy consumption in the air supply system. To clearly describe the characteristics of the air supplying device, an identification model of vane compressor is obtained through experiments. Since some of the state variables of the air supply system cannot be measured directly, the differential flatness method is utilized to estimate them. Then proofs of the global stability of the closed-loop air supply system with the feedback linearization is given. Simulation results show that that PEMFCs equipped with the proposed controller have good dynamic response performances under current variations.