Flatness and sliding mode based controller of fuel cell and supercapacitors hybrid source

In this paper, a nonlinear flatness and sliding mode controllers of a Fuel Cell and Supercapacitor (FC/SCs) DC-link voltage are proposed and validated by the simulation results. The nonlinear flatness strategy provides a simple way to achieve a linearizing feedback control law, which allows giving an exponential tracking of the desired energy references of FC and SCs. The ideas behind the proposed energy management controller are as follows. First, control the FC and SCs powers by using the flatness control strategy, which allows decoupling the system into two sources such that each subsystem has a separate control target expressed in terms of a sliding surface. Second, The sliding mode controller is used to ensure instantaneously the power sharing between the DC-bus converters, it ensures that the the SC and FC currents track well their references, which are calculated from the SC and FC powers. The proposed flatness-sliding control combination manages successfully the hybrid system energy with a stable and robust performances.