Research On Power Managing And Load Forecasting For Marine Electric Propulsion System

The power management system is an important part of the ship.Its function is to guarantee the power system operating stably and efficiently,as a result of which achieves maximum power supply and minimum fuel consumption,and can cooperate with other control systems,makes the whole ship perform maximally.With the development of power electronics and variable frequency speed control technology,electric propulsion system is widely used in modern ship.Due to the increasing power of propulsion system,and the emergence of new type high-power load,which put forward higher requirements to the ship power management system.Therefore,the research on power management system is of great significance to the electric propulsion ship,in order to solve the problem of power management system,this paper puts forward the improved measures based on the research of the ship load management and power generation management system.In terms of ship load management,this paper analyzes the characteristics of ship power system and the traditional load management strategy,proposes a improved load power controller based on fuzzy logic,this controller uses speed and acceleration signal of the generator as the input and uses the load power limit signal as the output.According to the expert experience,the fuzzy rule is designed.Compared with the traditional method of load management,fuzzy load power controller improves the response speed of power damand of large load and electric propulsion system.In terms of ship generation management,this paper analyzes the load impact on the generators that in normal operating state when a generator fails.In order to deal with the influence of the large amplitude fluctuation of the ship load on the generators,this paper analyzes the charging and discharging characteristics of lithium battery and super capacitor,uses the super capacitor as an intermediate energy storage device to control the fluctuation of the load of the ship by clipping the wave.The simulation results prove that the super capacitor enhance the ability of the power system to respond to the step change of the load power.In order to enhance the stability of the ship power grid,adopts the load forecasting method of the terrestrial grid,uses the historical load data base on time series as the training sample to train the Elman neural network,obtains the future load forecast as output.According to the forecast results,adjusts the generator starting reserved power,start-stop reserve capacity and the delay time of exiting power grid.Comprehensive analysis of load management,generation management and load forecasting,the ship power management strategy is improved.Finally,this paper builts the distributed real-time simulation platform using RT-LAB simulator and industrial control computers.Get the ship power generation system and the power management system model running in the RT-LAB simulator,get the load system model running in the industrial control computer,and the whole simulation of the ship power system is realized through the external data interaction between simulators.Building a simulation platform to test the improved ship power management strategy,results verify the superiority of the improved power management strategy.