Multi-Objective sliding mode control of proton exchange membrane fuel cell system based on adaptive algebraic observer

To improve the efficiency and extend the lifespan of the proton exchange membrane fuel cells (PEMFC), it is imperative to control PEMFC's supply system effectively. A sliding mode controller (SMC) based on adaptive algebraic observer is designed to control the oxygen excess ratio and the pressure difference between the cathode and anode of PEMFC. First, a 9th order physical model of the PEMFC system is established including air supply system, hydrogen supply system and the stack, which is validated against the experimental data with the maximum output voltage error of 2.91%. Then, a SMC is designed based on the control-oriented PEMFC model. An adaptive algebraic observer for the estimation of the gas partial pressure is designed to be used in the SMC. Finally, simulation is conducted and results show that the performance of the designed SMC is superior than that of the PID controller in terms of the oxygen excess ratio settling time (1s less), the pressure difference settling time (50% less) and overshoot (0.5 kPa less).