Noise Research On Permanent Magnet Brushless DC Motor

Since the recent decades, with the rapid development of with the high powersemiconductor switching devices, high performance permanent magnet technology, specialcontrol integrated circuit and drive control technology, permanent magnet brushless dc motorhas been rapidly development.It has the advantages of small volume, light quality, simplestructure, reliable operation, high efficiency, high power density and the flexible and varied inshape and size,etc.Permanent magnet brushless dc motor due to its own advantages, it hasbeen widely used in the various fields of national economy.Along with the extensiveapplication of permanent magnet brushless dc motor, gradually found that the motor vibrationnoise problems, therefore, research on the noise of the permanent magnet brushless dc motoris necessary. This article mainly from the following several aspects of permanent magnetbrushless dc motor noise problems are studied:（1）Briefly described the basic structure and the basic working principle of permanentmagnet brushless dc motor, and introduced the research status quo of the permanent magnetbrushless dc motor noise;（2）Briefly described the basic concept of the acoustic,including the acoustics and noisebasis. And introduced the motor’s electromagnetic noise generation mechanism, mechanicalnoise generation mechanism, ventilation noise generating mechanism;（3）Using the electromagnetic analysis software Ansoft, respectively analyzes thepermanent magnet brushless dc motor magnetic field under no-load and load conditions,obtaining the air gap flux density and the radial electromagnetic force of the motor, andanalyzes its characteristics and its connection with electromagnetic noise;（4）Using the inherent modal finite element analysis software Ansys, analyzing its theinherent modal analysis of2D and3D for motor stator core, obtained in previous order modalvibration mode and natural frequency and then the motor housing and the cover with thestator core were analyzed together in three intrinsic mode, reseached the impact on theexistence of the motor shell and cover to the natural frequency of the stator;（5）Briefly described the method of controlling the vibration noise, and put forwardsome measures for reducing vibration noise of permanent magnet brushless dc motor by usingthe method of control vibration noise sources;This paper studies the vibration and noise of the vibration source and puts forward somemeasures to reduce vibration and noise. This paper for further study permanent magnetbrushless dc motor noise provide certain foundation.