Simulation and control of reactants supply and regulation of air temperature in a pem fuel cells system with capacity of 50 kW

Nonlinear models of both a heat exchanger for cathode and a direct current electric motor to drive the compressor are sized and incorporated to the mathematical model of a PEM fuel cell system with capacity of 50 kW of net power intended to propel an electric vehicle. A balance of plant is achieved through several controllers to the main control loops. A Model Reference Adaptive Controller is used to regulate the oxygen excess ratio manipulating the voltage applied to the electric motor. Proportional-Integral controllers are designed to regulate the air temperature entering to the cathode and to minimize the pressure difference between the cathode and anode. Despite the non-minimum phase behavior observed in the net power delivered by the stack, the closed-loop system tolerates changes in current demand and keeps the compressor operating in its region of maximum efficiency.

Keywords: PEM Fuel Cell, MRAC, Heat Exchanger, Oxygen Excess Ratio.