Hybrid Energy Storage Systems for Voltage Stabilization in Shipboard Microgrids

Due to increasing environmental concerns associated with the fossil fuel consumption and greenhouse emissions by marine vessels, world is moving towards sustainable energy resources such as solar, wind and so on. Renewable energy sources are found out to be a significant source of energy as they are sustainable and clean as compared to traditional generation sources, for instance, the burning of fossil fuels, diesel generators, steam engines, etc. As solar energy is one of the cheapest, abundant and cleanest source of energy, therefore, it has the potential to be the most utilized source of energy along with energy storage systems (ESS) for future yachts and ferries. However, partial shading effect and intermittent nature of photovoltaic (PV) systems cause fluctuations in voltage that can potentially disturb the voltage profile, therefore may instigate instability in shipboard microgrids, if not properly managed. This paper, therefore, proposes a hybrid energy storage system (HESS) comprising of Lithium-ion (Li-ion) battery and ultra-capacitor having the capability to mitigate fluctuations caused by the partial shading effect in PV panels. The control system is based on frequency sharing approach in which high-frequency components are handled by the ultra-capacitor whereas low-frequency components are handled by the Li-ion battery. The proposed methodology is simulated using MATLAB/ SINULINK and various scenarios of power sharing are highlighted for the validation of the proposed scheme.