Optimization of fuel consumption in shipboard power systems

In order to comply with new stringent environmental regulations, and to achieve higher fuel economy, dc hybrid power systems are being considered for commercial marine vessels. In this paper, an optimization algorithm is proposed to minimize fuel consumption of a marine vessel under various loading conditions. The studied dc hybrid system includes diesel engines, synchronous generator-rectifier units, and a full-bridge bidirectional converter that incorporates an energy storage device into the system. In order to evaluate potential fuel saving provided by such a system, an online optimization control, based on the proposed algorithm, is implemented in simulation of an Offshore Support Vessel (OSV) over different operating modes. The simulation results show that the dc system without energy storage provides a fuel saving of approximately 7% compared to the conventional ac system. The comparison also shows that optimal utilization of the energy storage in the dc system would result in twice as much fuel saving.