Membrane humidity control of proton exchange membrane fuel cell system using fractional-order PID strategy

Abstract

Dynamic humidity control is a crucial factor affecting the working performance of proton exchange membrane fuel cell (PEMFC) system. Proper membrane humidity can guarantee power generation performance, improve energy utilization efficiency, prevent irreversible degradation of the proton exchange membrane (PEM). In this paper, a dynamic control model for PEMFC humidity management is proposed, and a fractional-order PID (PIλDμ) control strategy is introduced to balance the membrane humidity of PEMFC. The results show that comparing with traditional PID control methods, the PIλDμ control shows shorter response time, lower overshoot in membrane humidity control, and higher power generation efficiency in PEMFC system. In addition, the performance of the PEMFC using PIλDμ control method at different pressure and temperature conditions is discussed. The power generation efficiency of the PEMFC under PIλDμ control is improved, which is 2.1 %, 3.9 % higher than that of fuzzy PID and conventional PID control method.