Experimental study of extremum seeking control for maximum power point tracking of PEM fuel cell

The Ability to extract the maximum power of proton exchange membrane (PEM) fuel cell is the important issue for optimal design of fuel cell powered system. It is necessary to force the fuel cell to operate in a condition which match up with its maximum power point (MPP). MPP varies nonlinearly with the unpredictable variation in the fuel cell´s operation condition. Thus, a maximum power point tracking (MPPT) controller is needed to deliver the maximum possible power to the load when a variation in the operation condition occur. The proposed control system consists of two-loop cascade controller with a DC-DC converter. The outer loop uses extremum seeking control to estimate the real-time MPP, and the inner loop uses that estimated value as a set-point for hysteretic control to force the fuel cell to operate at the estimated MPP by DC-DC boost converter. Extremum seeking control and hysteresis control are implemented on a dSPACE DS1104 controller board. For the experiment setup, small scale energy sources are operated, which is Constructor 50 W 10 A fuel cell. Simulation and experiment shows that this proposed control can achieve satisfactorily the maximum power point of fuel cell.