Electric propulsion technology in the realm of marine shipping is more than a century old. Incorporation of technologies such as DC distribution and energy storage for vessels is further widening the horizons to look towards the same direction. DC Ships aid in the integration of variable speed diesel generators thus supporting the fuel consumption mitigation and controlling the emissions.
For alternative forms of energy to be tapped, energy storage systems would be required for optimal level of operations. Development has been vigorous in the rechargeable batteries domain to meet the ever so increasing demand in terms of energy specially to solve the intermittent nature of the power requirement in a DC ship in the event of mechanical/electrical breakdown. It is essentially important for the modelling of a cell to be used in such DC ships to track the state of charge, voltage level of the battery in real time by feeding in the physical state of the battery as an input.
An overview of working of different battery chemistries is done in order to conclude regarding the best kind which could be used for marine systems. Following this, a summary of the various equivalent models, starting from ideal model to DP model is obtained based on complexity. By understanding the different models, an equivalent model inspired from the Shephard's model has been implemented based on selection of points from the experimental curve so that it could be incorporated in a marine system to carry out fault management in a marine network. The model has been tested for 3 discharge rates to justify its robustness. The graph obtained from this battery model is then divided into two components to derive an electrophysical meaning by proving a strong correlation with the Single Particle Model under certain assumptions and a generalized exponential function.Master of Science (Power Engineering
