A hybrid fuel cell-supercapacitor system employing adaptive control to overcome fuel starvation phenomenon of fuel cell

摘要

Increase in research orientation in the field of structure and control of microgrids play a major role in seamless inclusion of clean energy into microgrids to suffice the conventional energy requirements. This paper presents a low voltage DC microgrid incorporating fuel cell based reliable clean energy generation and supercapacitor based transient energy storage device to form a stiff DC source for the local DC loads. Fuel cell stack and supercapacitor bank are interfaced to load terminals using a DC-DC boost converter and DC-DC bidirectional converter respectively. Dual loop control is used to establish control for these power electronic interfaces in order to facilitate stable power to the load irrespective of the constrained operating characteristics of the fuel cell and transient load variations. Proper power sharing, safe operation of the equipment and optimal control of state variables is achieved by employing the current control. A special case of SOC protection of supercapacitor is dealt in this paper. The proposed system along with the controller is tested for different transient R, R-L loads operating in an intermittent mode using MATLAB/SIMULINK modelling. The aftermath of the associated control action is a stabilized grid voltage (48V) with required power flow among microgrid participants in order to suffice the transient power requirements of the grid loads even after respecting the operating constraints associated with the microgrid participants.