Research On Simulation Of Energy Optimization Control Of Marine Hybrid Electric Propulsion System

Ships always consume massive energy during operation,so an increasing number of scholars pay more attention to the energy issues and fuel economy issues.The series of studies have the insightful and practical effect to improve ship operation efficiency and achieve energy saving as well as emission reduction goals.The rapid development of power electronics and energy storage technology has made the form of ship’s power system more diversified,so the application of energy storage elements in the traditional electric propulsion form of the ship’s hybrid electric propulsion system combines the advantages of energy storage technology and electric propulsion technology,which is an important way for the shipping industry to achieve the goal of energy conservation and emission reduction.In addition,the operational performance of ships can be improved in the method.Hence,how to design a reasonable and efficient energy control strategy with energy storage components has become a key point in the field of marine hybrid propulsion.In this paper,the energy optimization control problem would be deeply researched based on the typical marine hybrid electric propulsion system.The energy of the hybrid electric propulsion system would be analyzed at the first of the paper.This part includes the study of fuel consumption characteristics of diesel generators and the power loss of synchronous generators.The energy storage system adopts an active topology,and the mathematical models of lithium batteries and supercapacitors are established respectively.By studying their characteristics of charge and discharge and analyzing the applicable operating conditions respectively,the power loss model of the energy storage system is established.According to the analysis of load power in the hybrid electric propulsion system,the factors that can change the fuel consumption rate of the diesel engine is determined.On that basis,combining the different energy storage characteristics of lithium batteries and super capacitors,an energy optimization control that is suitable for marine hybrid electric propulsion systems is proposed.The strategy uses super capacitors to smooth the load power fluctuation by low-pass filter algorithms.Moreover,the strategy uses lithium battery packs to improve working condition of diesel generators.Based on the application of the minimum fuel consumption algorithm,the best number of online generators set and the optimal output power of the diesel generator can be calculated,which can realize the purpose of reducing fuel consumption.The innovation of the research is that can fully utilize the work characteristics of two energy storage elements in the hybrid electric propulsion system,smooth the load power fluctuation and optimize the fuel consumption rate of diesel engine.In order to verify the effectiveness of the proposed energy optimization control strategy,five sailing conditions(hauling,accelerating navigation,and transportation navigation in high,medium,and low sea conditions)are considered.According to the application of the strategy in the six working conditions,the calculation results of the number of diesel engines on the grid and the state of charge of the energy storage elements and the output power of the diesel generator are obtained.Additionally,the fuel consumption characteristics of the ship’s hybrid electric propulsion system without applying energy optimization strategy and the electric propulsion system under AC networking were compared and analyzed under the same sailing conditions.The results show that the research on the energy optimization control strategy of the ship’s hybrid electric propulsion system can effectively reduce the fuel consumption of the ship,which can also provide a theoretical insight for the application on the real ship.This paper has certain significance for improving the ship’s operating efficiency.