Fuel cell control systems : A practical case

This work proposes and justifies an easy electric model of a power generation system based on a PEM fuel cell, the Nexa Power Module of Ballard. This model has been developed by means of experimental data obtained in our laboratory. Moreover, as this system generates unregulated power, a DC/DC converter is designed and a control system based on state feedback is proposed. This control system guarantees that fuel cell system operates at maximum power point taking into account the limits current slope of power module because of the slow response of auxiliary mechanics components. Both the proposed electric model and the proposed control system, can be applied to any other PEM fuel cell system if the polarization curve along the whole output current rate and the maximum power point is known.