Fuzzy Sliding Mode Control of Air Supply Flow of a PEM Fuel Cell System

To reduce the danger of the oxygen starvation of the proton exchange membrane fuel cell (PEMFC) stack and improve the net power output of the PEMFC system, the air supply flow of the PEMFC stack must be regulated effectively. The nonlinear and time-variant characteristics of the PEMFC air supply system make it difficult to adjust its air supply flow for traditional control strategies. A fuzzy sliding mode controller (fuzzy SMC) with good robustness is proposed to control the air supply flow of the PEMFC stack in this chapter. An equivalent control is constructed based on the developed model of the PEMFC air supply system. A fuzzy logic inference mechanism is embedded in the traditional SMC to generate a smooth hitting control. Numerical simulations show that the proposed fuzzy SMC removes the chattering phenomena of the traditional SMC. Compared with the static feed-forward (sFF) controller, PI controller, and PI/sFF controller, the fuzzy SMC provides much better control performance of the PEMFC air supply flow.