Research On Capacity Optimal Allocation Of Multi Energy Ship Power System

The power of traditional ships mainly depends on diesel engines,and the fuel is gradually exhausted fossil energy.On the one hand,under the influence of the energy crisis,the price of traditional energy has been rising under the influence of the international situation;On the other hand,the international maritime organization puts forward higher and higher requirements for ship emissions.The traditional ship power mode is difficult to meet the new emission standards,forcing the ship power system to carry out energy transformation.With various types of energy entering the ship power system,how to optimally allocate the capacity of each energy is the primary problem to be solved.At the same time,the ship’s working conditions are complex and changeable during navigation,and the ship’s power load fluctuates accordingly.How to reasonably allocate the capacity of each energy under the premise of ensuring the stability of the power system for different ship types,different working conditions and different energy types is a difficulty.In this paper,by establishing the objective function of reasonable capacity optimization and energy constraints,In view of economy and environmental protection,the overall capacity optimal allocation is studied,and the optimal allocation scheme is finally obtained.The research object of this paper is a multi energy marine power system composed of diesel generator,lithium battery,photo voltaic panel and super capacitor through DC networking.By analyzing the principle and mathematical model of each power supply component,the simulation model of each power supply is built,and then the capacity optimal configuration scheme of hybrid energy storage system(super capacitor,lithium battery)and power generation system is studied.The specific research contents are as follows:Firstly,the principle of each component of multi-energy power system including super capacitor,lithium battery,diesel generator and photo voltaic cell is analyzed,and the mathematical model or circuit model is constructed.On this basis,the MATLAB /Simulink simulation model is established,and the correctness of the model is verified by simulation.Secondly,this paper takes the single group cost of energy storage elements,the number of single group of energy storage elements and the life loss condition of energy storage elements in the ship as the economic index,and the pollution gas discharged by diesel generator is converted into environmental protection conversion cost as the environmental protection index,so as to construct the objective function of capacity optimization allocation,and then take the micro source quantity constraint,distributed power generation output constraint The system power balance constraint,lithium battery charge discharge constraint and state of charge constraint are taken as the reliability indexes of ships,and the constraint conditions of capacity optimal allocation are established,so as to establish the capacity optimization model of multi-energy ship power system.Then,according to the multi-objective model and constraint model of multi-energy ship power system capacity allocation,particle swarm optimization algorithm and genetic simulated annealing optimization algorithm are used to optimize the capacity of the objective function.In the simulation process,particle swarm optimization algorithm is easy to fall into local optimization and does not deal with discrete optimization problems well,The search speed of genetic simulated annealing algorithm is too long,it takes more time to get an accurate solution,and it depends on the selection of the initial population.Therefore,this paper introduces the genetic simulated annealing optimization algorithm into the particle swarm optimization algorithm to form the simulated annealing genetic optimization particle algorithm.Before the particle swarm optimization algorithm updates the particles,the cross interaction process in the genetic algorithm is introduced to produce better offspring individuals.The simulated annealing factor is used to solve the problem that the genetic algorithm is easy to fall into local optimization.By analyzing the working load of different target ship types,different optimization algorithms are used for simulation calculation,and the optimal capacity allocation scheme is obtained.Finally,after obtaining the capacity optimization configuration schemes of two different ship types,the ship power system simulation model is constructed to analyze their performance under the sudden increase and decrease of load and various load conditions of slope load.The ship power system can work stably with small voltage and power fluctuations,It is verified that the capacity matching scheme obtained by simulated annealing genetic optimization particle algorithm is reasonable,and can ensure the stability and safety of ship power system under various load shocks.