Fault Analysis And Unbalance Compensation For Permanent Magnet Synchronous Motor With Air Gap Eccentricity

Compared with the traditional electro-magnetic motor, permanent magnet motor has a series of advantages, such as small volume, light weight, low loss, portable structure and reliable operation, and it has a broad application prospects in the field of energy, transportation, aerospace, etc., especially in China, which is rich in rare earth resources. It will be of great significance to China’s economic and social development to take full use of resource advantages to study and manufacture various kinds of permanent magnet motors which are represented by rare earth permanent magnet motor.Air-gap eccentricity fault is one of the common faults for permanent magnet motors. If the fault appears, unbalance magnetic pull will be generated between stator and rotor, magnetic field will be distorted, and there will be deterioration of motor’s performance indicators for good, and the rotor will rub against the stator for worse, which will cause a motor failure. Therefore, it is significant to study the performance of permanent magnet motor with air gap eccentricity fault and unbalance compensation for the rotor.Through the establishment of the dynamic model of permanent magnet synchronous motor rotor, this thesis studies the running performance of PMSM with air gap eccentricity fault, then proposes a method to compensate for the air gap eccentricity based on the additional control winding, and the validity of the method is verified through the simulation. The content of this thesis is arranged as follows:In Chapter1, the back view and the significance of this study are elaborated, the development of Permanent Magnet Motors is summarized, the main research contents and progress of the motor air gap eccentricity fault and unbalanced compensation are introduced, and then the research content and framework of this thesis are proposed.In Chapter2, the basic loads on the rotor system of permanent magnet synchronous motor with air gap eccentricity fault are analyzed, the commonly used control methods for permanent magnet synchronous motors are introduced, and then the criterion and principle of unbalance compensation for motor rotor are introduced, and finally the condition of the method which is used by this thesis is deduced.In Chapter3, taking the elastic supporting effect and the influence of external load torque into account, the dynamic model of rotor of permanent magnet synchronous motor with air gap eccentricity is built, and the running performance of the motor is studied by numerical method, and the influences of various parameters and external loads on the vibration response of rotor system are discussed in detail.In Chapter4, based on the control method with additional winding, the control model of permanent magnet synchronous motor is studied, then the composition of the control system is analyzed and designed with the MATLAB/SIMULINK tools, and the effectiveness of the proposed scheme is studied through the simulation calculation.In Chapter5, the main work of the thesis is summarized, and the further research work is prospected.