Electromagnetic Transient Algorithm And Simulation Platform Development Of Power Supply System For Urban Rail Transit

Electromagnetic transient simulation of urban rail transit power supply system is an effective means to study the structural stability of power supply system.Since the urban rail power supply system contains a large number of power electronic devices with nonlinear characteristics,such as PWM converters,diode rectifier units,etc.,in order to accurately simulate the transient characteristics of power supply system,the electromagnetic transient modeling and electromagnetic transient algorithm of urban rail power supply system are studied in this thesis,a piecewise average model based on the calculation subsystem to improve the EMTP algorithm is adopted,and a simulation platform for system level electromagnetic transient calculation of urban rail power supply is developed.In terms of electromagnetic transient modeling of urban rail power supply system,the structure and characteristics of the power supply system are analyzed,the electromagnetic transient model of each equipment in the urban rail power supply system is established,and the Norton equivalent circuit and calculation formula in the electromagnetic transient model of each equipment are derived,which provides the model basis for the subsequent realization of electromagnetic transient calculation.In terms of electromagnetic transient calculation of urban rail power supply system,the electromagnetic transient algorithm of the power supply system is studied,the basic principle and algorithm flow of the traditional EMTP algorithm and the segmented average model EMTP algorithm are analyzed,and the segmented average model is improved EMTP The algorithm is tested and verified,and the results show that the method adopts a larger calculation step to ensure the correctness of the simulation results.The improved EMTP algorithm of the segmented average model is applied to the electromagnetic transient simulation of the urban rail power supply system.In this thesis,a piecewise average model suitable for electromagnetic transient calculation of systemlevel urban rail power supply is used to improve the EMTP algorithm.the traction and step-down substations are divided into several subsystems with independent internal calculations.The calculation subsystems are calculated separately from the energy feedback subsystem and the rectifier unit subsystem,and the external state equations and sub-systems are solved simultaneously.The system characteristic equation obtains the electromagnetic transient calculation results of each node.In terms of the construction of electromagnetic transient simulation platform for urban rail power supply system,the overall structure of the simulation platform is designed,and the program is written from four modules: user interface,simulation configuration,simulation calculation and data processing.The algorithm layer,model layer,interface layer and database layer support the software hierarchy of the simulation platform.Based on Visual Studio 2013 platform,the graphical user interface is developed with C # language.The modular graphic element of WFP is established,and the element drawing and parameter design are combined to realize the self defining establishment of the component electromagnetic transient model.According to the designed graphical simulation interface,the EMTP algorithm and simulation interface are combined with the segment average model which is suitable for urban rail power supply system.At the same time,the idea of joint development of C # and SQL server is adopted to interact access database with C # program,not only can realize the electromagnetic transient calculation function of the power supply system,but also make the simulation platform have strong man-machine interaction.Finally,taking an actual line as an example,the electromagnetic transient function of the developed simulation platform for urban rail transit power supply system is tested.The results indicate that the improved EMTP parallel simulation algorithm for urban rail power supply system proposed in this thesis has good performance.The simulation platform can realize system level simulation model building and electromagnetic transient simulation of urban rail transit power supply system,and the calculation results accord with the actual situation of the project.Figures: 75,Tables: 8,References: 65.