Development Of Simulation System Of Ac-dc-ac Electric System

This paper aims at providing a basis for determining the control strategy and operating parameters of the system in the design of the traction system of the emu,and predicting the variation of operating parameters of the emu.Research is mainly focused on the cross-straight-to pay the operation of the electric traction drive control system control mode and process analysis model,set up to pay-direct-pay traction system simulation model,the system of traction motor,traction transformer,traction converter,and the change of operation parameters in the process of train running process simulation and analysis,to verify the traction drive system of traction and braking operation characteristics,simulated the traction and braking performance.Through the analysis of the obtained data,it provides the basis for the design of traction motor,traction transformer and traction converter,verifies the correctness and effectiveness of the traction motor vector control strategy,and provides effective data support for the development of the platform for train simulation driving.The research contents of this paper are as follows:(1)a process simulation model of ac-dc-ac traction drive system is established.(2)the working principle of PWM pulse rectifier,SPWM modulation strategy and the direct transient current control strategy are analyzed,and the generation of harmonics is analyzed.(3)the space voltage vector of the two-level inverter is analyzed,and a two-level SVPWM control algorithm based on the coordinate system widening is established.The principle of vector control of traction motor and the mathematical model of indirect vector control of asynchronous traction motor are analyzed.(4)taking CRH3 emu as an example,the control process of traction,braking and constant speed is analyzed,and the variation rules of traction force and braking force parameters of traction system during operation are analyzed.It provides the basis for parameter design of traction motor,traction transformer and traction converter.(5)the simulation software is used for the simulation analysis of traction motor vector control,the four-quadrant rectifier simulation model and the two-level inverter simulation model.The simulation parameters and working conditions of four-quadrant pulse rectifier,direct current circuit simulation parameters,traction motor parameters and CRH3 emu are set.The simulation results were analyzed,and the traction braking characteristics were optimized through simulation data analysis,and the validity and correctness of the parameter design of traction transformer,traction converter and traction motor were verified.(6)the technical method adopted by the simulation system can be used to analyze the working process and predict the performance of the traction drive system of the emu,and provide parameter basis for the design of the equipment in the traction drive control system.