Experimental validation of an output feedback controller based on an integral and adaptive backstepping technique for a fuel-cell power system

The present work establishes a comparison between two controllers based on a backstepping approach for a fuel-cell power system. The load resistance representing the impedance of the dc bus is assumed to be unknown and can change. Besides, the internal fuel-cell voltage is not accessible for measurement. Therefore, to cope with these two issues, two output feedback controllers are designed using a backstepping technique. The first controller uses an integral action while the second one is an adaptive version of the former. It is formally shown using theoretical analysis and simulation that the obtained controllers achieve all control objectives. A comparison between the two controllers shows that, when they are correctly tuned, both behave almost similarly. Nevertheless, we noted the weak supremacy of the adaptive version over the integral version in terms of rapidity. A laboratory prototype is built to show the effectiveness of the proposed control approaches.