Supercapacitor-based transient power supply for DC microgrid applications

Energy storage systems have become inevitable components of a DC microgrid in terms of pacifying voltage/current fluctuations that are unavoidable due to the unpredictable, intermittent nature of renewable energy system and load. These fluctuations normally result in power quality issues in addition to stability issues. The transient pressure on the DC bus increases with an increase in distance between the source and load. Further, it affects the other connected loads in a single-bus system. Hence, this paper proposes a multi-bus dc microgrid structure integrated with a supercapacitor transient power supply to deal with the fluctuating DC loads. In the proposed model, the steady-state power requirement of the load is expected to be met by the DC bus, while the dedicated supercapacitor bank would compensate for the transient power requirements. The proposed model has been developed and simulated in MATLAB/Simulink. The simulation results shows that the proposed scheme is capable to reduce the transient pressure on the DC bus and improve the power quality of the DC microgrid. Also, hardware experiments have been conducted to validate the accuracy and feasibility of the proposed system.