Electric power consumption predictive modeling of electric propulsion ship considering the marine environment

Abstract

An electric propulsion ship (EPS) moves forward by using a propeller rotated by a propulsion motor (thruster). During the forward motion, a power system supplies electric power to the propulsion motor. The power system is an important system and it generates, supplies, distributes, and manages the electric power consumed at not only the propulsion motor but also the electrical loads on the ship. The electric power of the propulsion motor accounts for a larger proportion of the total electric power consumption than any other electrical load. Therefore, the maximum capacity of the generator and the specification of the electric equipment should be determined according to the electric power consumption of the propulsion motor. The ship type, main dimensions, and marine environment should also be considered because the electric power consumption of the propulsion motor changes continuously in accordance with these components. An efficient design is possible via accurate electric power prediction. There are difficulties in testing and validating the function of the power system in the basic step of design. Hence, empirical formula or a similar ship are used for the prediction of electric power. In this study, we performed simulation modeling for the prediction of electric power consumption that varies with the marine environment. The marine environments considered are wave, wind, and current. The simulation model includes the “ship motion model” and “electric power consumption model.” The propulsion motors at the stern and bow were assumed to be the main electrical loads for the model. The model proposed in this study can be used to predict the electric power consumption of an EPS and it also determines the maximum capacity generated, and the specifications of propulsion motors and electric equipment.