Oxygen Excess Ratio Controller Design of PEM Fuel Cell

Abstract

The work of this paper focuses on oxygen excess ratio control, for the oxygen excess ratio has a great influence on the performance of the proton exchange membrane (PEM) fuel cell. To model dynamics of air supply system and oxygen excess ratio, a validated three-order model is used for controller design. Because the pressure of the cathode is unmeasurable in the actual system, a state observer is designed to observe the cathode pressure based on the third-order model. A controller combining with feedforward control and feedback control based on LQR method and map that can output the equilibrium state, feedforward control signal and feedback gain calculated off-line at different equilibrium points through the input of the expected oxygen excess ratio and load current is then designed. At last, oxygen excess ratio control strategy under different working conditions is realized and the simulation results verify the effectiveness of the proposed controller.