The modelling and three-level control of a hybrid propulsion system for a green ice-capable ship

Abstract

The decreasing of Arctic sea ice provides opportunities for commercial shipping between Asia and Europe due to its shorter distance. However, the Arctic environment is vulnerable to the pollutants from shipping activities. Therefore, it is important to consider the impacts of shipping activities in the Northern Sea Route (NSR), especially with a view to the possibility of reducing emissions of short-lived pollutants. In this paper, modelling of a hybrid propulsion system is conducted and implemented in Matlab Simulink. A 3-level control strategy with efficiency of power sources taken into consideration, is applied to ensure stability of voltage and frequency, as well as reducing the pollutants through minimizing the fuel consumption. A target journey with specific loading condition, which is related to NSR shipping, has been conducted to test the performance of the hybrid propulsion system with the 3-level control strategy and diesel electric system, the simulation results of the hybrid propulsion system applied with the three-level control strategy in this research can offer up to 22.7% fuel savings compared with a DC diesel electric system over a typical operating cycle. This justifies the use of hybrid propulsion as a more environmentally friendly propulsion system for the future ice-capable ships in the NSR. Finally, a sensitivity analysis is conducted to find the main factors, which influence fuel consumption.