Second order sliding mode control of the moto-compressor of a PEM fuel cell air feeding system, with experimental validation

Fuel cells are electrochemical devices that convert the chemical energy of a gaseous fuel directly into electricity. They are widely regarded as potential future stationary and mobile power sources. The response of a fuel cell system depends on the air and hydrogen feed, flow and pressure regulation, and, heat and water management. In this paper, the study is concentrated on the air subsystem that feeds the fuel cell cathode with oxygen. An IP control, a RST regulator and a higher order sliding mode control, super-twisting algorithm, with variable gains, have been designed and validated experimentally to control the air flow of the moto-compressor system, composed of a DC motor driving a volumetric compressor of type piston, designed to feed a 500 W fuel cell with air. Experimental results show better performance with the sliding mode control, especially when dealing with a delayed air flow sensor response.