Flatness based control of a dual active bridge converter for a fuel cell application

Based on the properties of flatness system, this paper proposes a nonlinear control for a dual active bridge converter for fuel cell applications. This converter is connected to fuel cell via a diode and an LC low-pass filter. The constraint of fuel cell like the maximum power and current slope are taken into account by means of the control of the energy stored in the filter capacitor corresponding to the fuel cell voltage obtained from its static characteristic. The diode and parasitic resistances are modeled as a series resistance connected to the fuel cell and its value is estimated and is used in the control algorithm. The effectiveness of the proposed system is demonstrated via experimental results.