The Influence On Vibration And Noise Of Permanent Magnet Synchronous Motor By The Random Modulation Strategy

In order to reduce the vibration noise caused by motor, it can reduce the vibration from designing motor ontology structure and its material and control strategy. As for control strategy,traditional SVPWM technology open and close semiconductor devices at a fixed frequency, so that it can cause larger current harmonics which cause motor vibration acceleration at switching frequency and its times around resulting in noise. Adding random factors can reduce current harmonic amplitude, however, so far people are still limited to analysis current harmonic, the motor vibration acceleration and vibration noise do not be studied.This thesis studies the output current harmonic, motor vibration acceleration and vibration noise with traditional SVPWM control function, random switching frequency SVPWM control function and random position SVPWM control function. This thesis builds simulation models and experiment platform to verify the result with permanent magnet synchronous motor.Firstly, the thesis introduces the development and application of random modulation technique. And then it introduces the principle of traditional SVPWM control method, random switching frequency SVPWM control method and random position SVPWM control method.Secondly, the thesis starts to simulate with three different control strategies by MATLAB/SIMULINK, and analysis current harmonic.Finally, measure the current harmonic and the vibration acceleration of traditional SVPWM control method through the experiment, and it can calculate the response coefficient. And according to the response coefficient the vibration acceleration of random switching frequency SVPWM modulation and random position SVPWM modulation can be calculated. Random switching frequency SVPWM and can effectively reduce the harmonic currents and vibration acceleration at switching frequency and its times around, the harmonic currents and vibration acceleration of random position SVPWM spread continuously and uniformly.