Direct current control of a battery-ultracapacitor power supply

We propose to use a model predictive controller in combination with direct current controllers to control the total current that is supplied or stored by a battery-ultracapacitor power supply. The model predictive controller is designed using models of a commercially available lead-acid battery cell and an ultracapacitor. Both the battery and the ultracapacitor voltages are fed back to the model predictive controller in order to improve the robustness of the system to model possible mismatches. The main advantage of the proposed system is that it adjusts how the total current is shared between the battery and the ultracapacitor. Simulation results show that the system performs satisfactorily and the total current is shared between the battery and the ultracapacitor subject to specified constraints.