Advanced control for fuel cells connected to a DC/DC converter and an electric motor

The transient behavior of a polymer electrolyte membrane fuel cells (PEMFC) system under an improved adaptive predictive control with robust filter (APCWRF) is analyzed using a nonlinear dynamic, control-oriented model. Sudden changes in the stack current are associated with the abrupt changes in the power demanded by the electric motor of a vehicle, powered by the PEMFC. The APCWRF is designed for controlling the compressor motor voltage. Because of the wide working range the control algorithm is improved accounting three different zones supported by three nominal models. It is specially thought to achieve a better efficiency and to maintain the necessary level of the oxygen in the cathode to prevent short circuit and membrane damage. A DC/DC converter is connected to the electric motor. It is used as an actuator in a cascade control loop to regulate the torque output of a DC electric motor with a PI controller in the external loop. Several results are presented considering the PEMFC with the APCWRF showing its potentiality for a wide working range imposed by two types of DC motors.