Research On Sensorless Control Of Permanent Magnet Synchronous Motor For Mine Electric Locomotive

In recent years,mining electric locomotives driven by permanent magnet synchronous motors have been gradually popularized in mines.Narrow tunnels and harsh working conditions such as humidity,high temperature and dust have greatly increased the possibility of physical sensor damage on permanent magnet synchronous motors.When the speed/position sensor on the permanent magnet synchronous motor is damaged,it is difficult to repair in a narrow space,and it will cause work stagnation and even casualties.Therefore,in-depth study of the sensorless control technology of the permanent magnet synchronous motor of the mine electric locomotive,eliminating the original encoder of the permanent magnet synchronous motor to detect the motor speed/position,is the key to improve the reliability and safety of the permanent magnet synchronous motor of the mine electric locomotive.According to the actual operating conditions of the mine electric locomotive,this paper divides the research of the permanent magnet synchronous motor sensorless control technology into two parts: the zero-low-speed stage,the medium-high-speed stage,adopts theoretical modeling,numerical simulation,and experiment methods to realize the mine motor sensorless control of the permanent magnet synchronous motor of the vehicle in the full speed domain.The research work mainly includes:(1)Research on vector control of permanent magnet motor under load characteristics of mine electric locomotive.Establish the mathematical model of the permanent magnet synchronous motor and combine the load characteristics of the mine electric locomotive to construct the permanent magnet motor vector control model under the load characteristics of the mine electric locomotive;use MATLAB/Simulink simulation software to compare the actual load and load conditions of the mine electric locomotive.The limit step load is simulated and verified to verify the correctness of the vector control method;the detection of data loss and inaccurate detection accuracy by simulating physical sensors is used to analyze the impact of sensor problems on the operation of the mining electric locomotive;according to the mining motor Based on the characteristics of vehicle operation,the sensorless control strategy of permanent magnet motor is selected.(2)Research on sensorless control technology of permanent magnet motor in zero and low speed domain based on high frequency signal injection method.The traditional single high frequency injection method has low accuracy in estimating rotor position and motor speed,poor system dynamic performance,and rotor position estimation errors when encountering sudden loads.A method of injecting dual high-frequency pulsations into the stationary coordinate system is designed.By injecting highfrequency pulsation signals into the stationary coordinate system,the position-related information in the response current is extracted,and the rotor position is obtained through the arctangent function;it is built using MATLAB/Simulink.The simulation model and the "Dynamometer-Permanent Magnet Synchronous Motor" experimental platform verify that the new sensorless method can improve the accuracy of estimating the motor's speed and the motor's rotor position.(3)Research on high-speed domain sensorless control technology of permanent magnet motor based on sliding mode observer.Aiming at the chattering problem caused by the sign function as a switching function,a hyperbolic tangent function sliding mode observer method is proposed.By optimizing the switching function,the use of a lowpass filter is reduced,and the phase-locked loop is used to extract the rotor position of the motor;further design the compound switching function in the middle speed domain is used.The speed switching area is defined according to the actual application range of the permanent magnet motor sensorless control methods of the two mining electric locomotives,and the weighted switching function of the transition interval is designed to realize the sensorless control of the full speed range.Simulation and experiments show that the improved sliding mode observer improves the dynamic performance of the system and improves the estimation accuracy of the permanent magnet synchronous motor's rotor position and motor speed.The paper has 68 pictures,6 tables,and 95 references.