Research On Speed Sensorless Technology Of Bearingless Synchronous Reluctance Slice Motor

As China enters the ranks of innovative countries,the 20 th National Congress of the Communist Party of China requires that the theme of promoting high-quality development be adhered to.It is also required to organically combine the implementation of the strategy of expanding domestic demand with deepening the structural reform of the supply side.This makes China need a stronger electrical transmission system.However,international rare earth prices continue to rise,and commonly used permanent magnet materials usually require a large amount of rare earth resources.How to use non permanent magnet motors to replace permanent magnet motors has become an important aspect of motor design.The bearingless synchronous reluctance slice motor(BSyn RSM)is a new type of motor that can be used in highly clean and environments which is difficult to maintain.And it has some outstanding advantages such as frictionless and high speed.The traditional speed sensor system makes it difficult to miniaturize the motor,increases the cost of the motor,and has a negative impact on the reliability of the motor.In the past,speed sensorless detection methods usually did not consider the effect of the suspension force winding,which reduced the detection accuracy.A speed sensorless system considering the effect of the suspension force windings will effectively solve the above problems.In this dissertation the BSyn RSM is taken as the research object.Based on the working principle,the mathematical model is built,and the effect of suspension force winding on torque winding,speed sensorless control system,and digital control system is researched.The main work and achievements are as follows:1.In this dissertation,the research background of the bearingless slice motors is described,and the research status of the bearingless motor at home and abroad is summarized.The development of the speed sensorless control of bearingless motors is summarized.After analyzing the basic structure and the working principle of the BSyn RSM,a mathematical model of the BSyn RSM is derived.2.Mathematical model of the BSyn RSM is conducted in finite element software to analyze the effect of the suspension force windings on the torque windings.The additional torque and additional current generated in the torque windings are analyzed.The BSyn RSM model considering the effect of the suspension force windings is constructed in Matlab/Simulink.Based on the established Matlab/Simulink model,the effect of the suspension force windings on commonly used high-frequency injection method speed sensorless systems and sliding mode observer(SMO)speed sensorless systems is analyzed.The simulation results show that the speed sensorless system using current or torque signals in the observed parameters will have higher estimated rotational speed vibration due to the effect of the suspension force windings,and the system stability will be reduced.3.In order to reduce the effect of the suspension force winding on the speed sensorless system,an improved SMO speed sensorless control system is proposed.The hyperbolic tangent function is used to replace the original switching function in the SMO system,and the phase locked loop system is used to replace the arctangent function to measure the obtained back electromotive force.By analyzing this model,the estimated vibration amplitudeb and frequency caused by the suspension force windings is effectively reduced using the improved SMO speed sensorless control system.The stability of the system operation is improved..4.To reduce the effect of the suspension force winding on the switching process of two speed sensorless control systems,medium to high speed and low speed,a switching function is used instead of a hysteresis comparator.And the improved particle swarm optimization algorithm is used to optimize the switching function.Finally,the full speed domain BSyn RSM speed sensorless control system based on the optimized switching function and improved SMO system is constructed,and the simulation experiments are conducted.From the simulation results,the proposed speed sensorless control method has good static and dynamic performance.5.The digital control experimental platform is constructed,the hardware circuit and software control system of the motor are designed.The BSyn RSM Hall sensor rotational speed measurement system is improved.The proposed speed sensorless control strategy is validated using the constructed experimental platform.