Research On Hybrid Energy Storage Control Strategy And Capacity Allocation Optimization Of Marine Electric Propulsion System

With the continuous depletion of fossil fuel in the world,the traditional internal combustion engine as a device that has emerged the trend of leaving the historical stage,and the ship’s whole electric propulsion system has been more and more attention by all countries.In this paper,a hybrid energy storage system(HESS)is designed based on a ship power grid structure to eliminate the fluctuation of the bus voltage.Firstly,according to the typical topological structure of the communication electric propulsion system,this paper analyzes and simulates the principle of each part of the propulsion system,including the prime mover part(gas turbine and diesel engine),the generator part,the propulsion motor part and the load propeller.Secondly,according to the voltage and current characteristics of lithium iron phosphate battery and super capacitor,the equivalent models are established and simulated.After confirming the topological structure of hybrid energy storage device,the model of HESS can be built,and the parameters of each part of the model are calculated in detail,and the simulation of the hybrid energy storage system is carried out to verify its correctness.Then,according to the characteristics of marine electric propulsion system,the control strategy of hybrid energy storage system is formulated,including the charge and discharge rules of super capacitor and lithium iron phosphate battery,over charge and over discharge protection and maximum power limit control.The whole marine electric propulsion system including hybrid energy storage system is simulated,and the hybrid energy storage system is tested under the conditions of reverse and sudden start and stop The validity of.Finally,the life wear model and the equivalent cost model of the hybrid energy storage system are given.The total cost of the energy storage components is optimized by the improved particle swarm optimization algorithm according to the constraints,and the cost is reduced without affecting the energy storage effect,and the simulation is carried out.