Research On Experimental Device Design And Control Algorithm Of Electric Locomotive Converter System

The electric traction AC drive system,as the core technology of electric locomotives,provides the driving force for the operation of locomotives and ensures the safety,reliability and rapid operation of trains.So it is necessary and significant to do further research on this system.Based on the electric traction AC drive system of electric locomotive,this paper studies the control strategy of the four-quadrant rectifier and three-phase AC asynchronous motor.At the same time,it designs the experiment device of the electric locomotive system,and verifies the feasibility of the control strategy.This experiment device provides a platform for professional and technical personnel training and students teaching.Firstly,the paper expounds the working principle of the four-quadrant rectifier in detail.The focus is put on the analysis of the transient direct current control strategy.The simulation model of four-quadrant rectifier is built in Matlab/Simulink,and this model is used to simulate the operation of traction condition and braking condition of electric locomotive.The simulation results show that the transient current control strategy has good dynamic response and steady-state characteristics,which is an ideal four-quadrant rectifier control strategy.Secondly,the mathematical model of three-phase AC asynchronous motor is established,and the simulation model of vector control system for asynchronous motor was built accordingly.At the same time,the speed sensorless control technology of the three-phase asynchronous motor has been studied in depth,that is,the model reference adaptive method is used to realize the speed identification of the three-phase asynchronous motor.In order to solve the problem of adaptive algorithm PI controller,this paper adopted sliding mode controller instead of the adaptive algorithm PI controller,is used to improve the traditional mode reference adaptive system,and then through the asynchronous motor speed sensorless vector control system to verify its good speed tracking effect.Finally,the design of the experimental device for the electric locomotive converter system is completed,that is,the TMS320F28335 chip is used as the main control chip,and the intelligent power module is used as the main circuit.The four-quadrant rectifier control and the sensorless vector control of the asynchronous motor are realized through voltage and current detection.Through experiments,the correctness and effectiveness of the control algorithm are verified.