Modeling And Steady-state Analysis For Ship Electric Propulsion System

Owing to the decreasing number of fossil energy source, the electric propulsion technology has drawn more attention. Different from the traditional propulsion, electric propulsion owns a lower energy consumption and greenhouse gas emissions. It is deeply meaningful to apply the electric propulsion technology into the ship system and analyze its steady and dynamic performance.This study focuses on the study of the electric propulsion in a ship system. All electric components of the ship system are modeled and various operational conditions are considered in the analysis of steady state and transient progress. The main contents are shown as follows.1) Establish the mathematical model of whole power system on a barge. After analyzing the components of the ship system, this paper set up a whole electric propulsion system including the diesel generator combined with a speed governing system, a distribution system, the transformers, different types of the motors, and the propeller.Furthermore,each model is programed by Microsoft Visual Studio2010 and enclosed by MFC technology.2) Analyze the steady state of the ship system. Firstly, set up a steady state analysis model based on the information which is stored in each node by the network topology technology. Then, calculate the power flow of the whole ship power system and obtain the torque of the propellers. Finally, compare the results with other simulation software to demonstrate the effectiveness of the proposed method.3) Analyze the dynamic performance of the electric propulsion system. There are four operating situations of the electric propulsion system, which are starting, braking,accelerating, and decelerating. This study analyzed the detailed transient progress when the electric propulsion system changed the operating condition. Moreover, the variation of the ship loads is also taken into account. Additionally, fourth order Runge-Kutta method is utilized in this paper to solve the mathematical model of the whole ship system.4) In order to optimize the controlling parameters, particle swarm optimization (PSO)algorithm is introduced into the control strategy. The simulation results proves that the efficiency of the proposed model and method.