Research On Traction Motor Transient For The Passing Neutral Section Of Electric Locomotive

As the carrier of electrified railway, electric locomotive is one of the important equipments of railway transportation, when the Electric locomotive passing neutral section, the Electric locomotive states frequent changes and in different transient process, this process will produce impulse voltage or current of high amplitude, which lead to electric locomotive converter, frequency conversion device, equipment breakdown and damage, which seriously affect the normal of railway transportation, So the global academia, electric railway operators,regulators have carried out the research work on the passing neutral section of the electric locomotive, in order to ensure the safe operation of the locomotive Based on the CRH2 electric locomotive as the research object, According to the working principle of the traction motor, the mathematical model of the electric locomotive is established by the method of voltage equation, flux equation, torque equation, motion equation; The traction motor mechanism of transient process and thetraction motor transient characteristics of electric locomotive passing neutral section are systematically studied, and the factors that affect the transient change of the traction motor are analyzed; Using Matlab/Simulink, combined model reference adaptive control system with car network dynamic model, the passing neutral section of traction motor speed identification be realized, the traction motor transient performance be optimization, and the traction motor vector control accuracy be improved. The main research contents are as follows:(1)A few of the most common types of electric locomotives passing neutral section are summed up, and the mechanism of electric locomotives passing neutral section over-voltage be studied, The effects of Transient Over-voltage on the current, output torque, speed and efficiency of the traction motor are analyzed.(2)According to the basic structure of the traction motor, working principle and the constraint relationship of the between stator and rotor,the motion equation of the traction motor in ABC coordinate system and??0 coordinate system and basic principles of vector control are analyzed,The mathematical model of the traction system of electric locomotive is established by using the voltage equation, flux equation, torque equation,motion equation.(3)Based on the CRH2 electric locomotive as the research object, The transient process and transient characteristics of the traction motor in thepassing neutral section over-voltage reduce stage and over-voltage rise stage are studied, and the factors of affecting the transient change of the traction motor are analyzed. Over-voltage reduce stage, traction motor terminal voltage decreases, the magnetic flux will be reduced, stator current and rotor current of the traction motor will be reduced, the stator q axis current, the output torque, and the speed are reduced;(4)A combined dynamic simulation model based on model reference adaptive instantaneous reactive power identification is proposed, The simulation platform was constructed by Matlab/Simulink, the speed of the traction motor was identified, the transient performance of the traction motor was optimized, and the accuracy of the vector control of the traction motor was improved.Through the research on the transient process of the traction motor of the CRH2 electric locomotive, The mechanism of over voltage generation of electric locomotive passing neutral section is found out, The effects of transient over voltage on the current, output torque, speed and efficiency of traction motor are analyzed, transient process and transient operating characteristics of traction motor in the process of passing neutral section over-voltage reduce stage and over-voltage rise stage are studied, The speed identification of the traction motor in the process of passing neutral section is realized, The transient characteristics of traction motor is optimized, and it provides the theoretical support for the safe operationand the system design of electric locomotive.