Research On The Credibility Evaluation And Optimization Of Ship Electric Propulsion Simulation

With the development of power electronic technology in the field of high-power transmission and transmission control system technology,the technology of electric propulsion has also been made a breakthrough.Electric propulsion can make the ship's kinetic energy device lighter,smaller,more flexible,more reliable and more economical,so it has emerged as an effective way of propulsion in various types of ships in recent decades.Due to the factors of cost,safety and environmental constraints,simulation is another effective research method instead of actual test,and is often applied in the research and design of ship electric propulsion system.But due to the limitation of the technology itself,the actual test can not be exactly the same with the corresponding simulation of ship electric propulsion,so in order to ensure the ship electric propulsion simulation plays a positive role in the process of research,we need some effective evaluation theory and methods to evaluate and optimize the credibility of electric propulsion simulation.Therefore,this paper focuses on the research and discussion about the evaluation and optimization on credibility of ship electric propulsion simulation,and the main contents are as follows.1.In order to obtain the research sample to study the evaluation theory and method of ship electric propulsion simulation credibility,build a experiment platform composed of the off-line simulation platform based on SimPowersystem and semi physical platform based on APPSIM and Arduino real time controller system of the ship electric propulsion simulation.2.According to the characteristics of ship electric propulsion technology,set up the evaluation model and give some typical examples.And to research the method to determine the weights of the evolution model,propose an algorithm based on Improved Fuzzy Analytic Hierarchy Process(FAHP)group evaluation method for system evaluation model,it can change with the appropriate punishment for some credibility lower unit,to fully characterizing the phenomenon that the influence of a low credibility unitis on the overall is larger,and illustrate the calculation process and characteristics of determining the weights of the evolution model.3.For the qualitative index,the accuracy of model expression,in ship electric propulsion credibility evaluation,this paper provide a comprehensive analysis method,which is first marked by experts according to the set of comments,and then combined with other quantitative analysis results through fuzzy comprehensive evaluation.The comprehensive evaluation of qualitative and quantitative indexes in the credibility evaluation of ship electric propulsion simulation is solved.4.Different analysis methods are studied for the evaluation indexes of different data types of simulation results.For the more stable signal data,we use the improved grey correlation analysis method.For the complex signal in frequency domain,we use improved grey relational analysis method combined with the wavelet transform.For index data,we do quantitative analysis based on the tolerance error.To solve the problem of the difficulty to apply the general analysis method because ship electric propulsion simulation result data contain different physical meaning and many types.5.In the process of ship electric propulsion simulation,some parameter ranges of a model are always known,but it is difficult to get the accurate parameters that match the simulation object by direct measurement or theoretical calculation,and the credibility of ship electric propulsion simulation is low.For this paper provide a method that using orthogonal design experiment to obtain the test sample,then using support vector regression method to regression the relationship model of the ship electric propulsion simulation results similar and modle parameters,finally using particle swarm optimization method to optimize the parameters of simulation model,instead of selecting the parameters of simulation model by comprehensive test.To solve the problem of time consuming,high cost and low efficiency in carrying out the comprehensive test,we can estimate the model parameters that can meet the requirement of ship electric propulsion simulation credibility with fewer test samples.