Research On Traction Control Strategy For Parallel Operation Of Asynchronous Traction Motor

AC drive technology has a series of advantages,such as large traction force,good adhesion performance,superior traction braking performance,etc.,and is widely used in the electric traction drive system of railway vehicles in China.At present,the ac drive system with three phase asynchronous traction motor,when the use of controlled or car driving mode,namely a traction inverter drive two or more traction motors in parallel work,due to the characteristics of the shunt motor parameter and wheel size differences,will lead to shunt motor output torque,power imbalances,The difference of motor characteristic parameters is mainly manifested as the difference of rotor resistance.Therefore,in order to alleviate the imbalance of output power and torque of the parallel motor as much as possible,the control strategy of the parallel motor is studied by comprehensively considering the influence factors of rotor resistance difference and wheel diameter difference.In this paper,first of all,the asynchronous motor traction drive system main circuit structure,the basic principle of asynchronous traction motor vector control is analyzed,and then analyzes the characteristics of the motor parameter and wheel size differences of two parallel motor output torque and power imbalance,the influence of the rotor field-oriented vector control theory of asynchronous traction motor indirect,on the basis of A vector control algorithm for parallel motors with average rotor field orientation is proposed.This paper proposes a working process of the asynchronous traction motor and joint simulation method of train operation process,asynchronous traction motor by indirect vector control algorithm,the working process of the asynchronous traction motor were established on the joint simulation model and the train operation process and the corresponding simulation system,on this basis,the combination of parallel operation of asynchronous traction motor control algorithm,The simulation model of parallel operation control system of asynchronous traction motor is established.Through system simulation,master-slave method and the average of the shunt motor rotor field-oriented method,comparing the two control methods,respectively discusses the rotor resistance differences only,there is only difference,and at the same time there are three difference in wheel diameter,verified in either case,the average rotor magnetic field orientation method has a more superior control performance than master-slave method.For the inevitable difference of rotor resistance and wheelset diameter,a matching scheme of wheelset diameter and motor parameters was proposed.