HYBRID SHIP HESS ENERGY MANAGEMENT SYSTEM DESIGN USING MPC

Abstract

A ship experiences different sea conditions during sailing. Particularly in adverse conditions, the ship generator will be put under extreme loading stress due to power fluctuations. This could potentially damage or shut down the generator. Having a Hybrid Energy Storage System (HESS) reduces the loading stress on the generator, as it can take over as an alternative power source. The goal of the thesis is to design a control strategy using Model Predictive Control (MPC) to effectively control the HESS output behaviors in order to compensate for power fluctuations due to ocean waves. For the purpose of this thesis, the HESS is composed of a combination of batteries and supercapacitors. Computer simulation using MATLAB verified that the MPC is able to effectively control the HESS in compensating for power fluctuations, and, at the same time, minimize generator overload. Different weightages on the battery were also tested to observe the battery and supercapacitor output behaviors. The simulation also provided insight into the impact of the weightages on the states and inputs, and it was observed that there is saturation on the battery and supercapacitor currents when their weightage difference is greater than 20. In addition, the model could also be used for preliminary study for HESS sizing based on the project power demands.