Distributed Scheme for Main Engine Power Control Systems of Small and Medium Sized Container Ships Based on Nash Equilibrium

As a main force of ocean shipping, the energy consumption of container ships is considerably high due to the frequent load shifts of main engine and other disturbances. In this study, for engine room power systems in intelligent container ships, including cooling water subsystems, fuel oil subsystems, and main engine subsystems, a coordinated control scheme based on a correlation model and a distributed model predictive control approach was proposed to reduce continual fluctuations of control and output values through optimisation in a negotiated manner. The correlation model considers the interconnections among the subsystems, and the control approach achieves Nash equilibrium solutions. A comparative simulation was carried out between the proposed method and the decentralized model predictive control. The result shows that the proposed method works better than the decentralized one with less fluctuations. This study provides a theoretical basis for integrated designs of power control systems in intelligent container ships.