Research And Design Of A Miniwatt Permanent Magnet Brushless DC Motor

The characteristics of the permanent magnet brushless DC motor are environmental,energy-efficiency,small size and multifunctional.The miniwatt permanent magnet brushless DC motor is a electromechanical integration product with superior performance,favored by people in the 21 st century,therefore it is widely used in medical equipment,precision instruments,aerospace and other fields,however,there are still high research value and development space in the permanent magnet brushless DC motor,this paper will research the permanent magnet brushless DC motor from the following aspects:1.Through the relevant data of a large number of permanent magnet brushless DC motor of literature researches,the application prospect of permanent magnet brushless DC motor is summarized,the current development trend of the permanent magnet brushless DC motor is discussed and the research status at home and abroad is provided.According to the basic principle of the motor,the permanent magnet brushless DC motor mathematical model is deduced,and three kinds of job characteristics——the starting characteristics of permanent magnet brushless DC motor,mechanical properties and regulating characteristics are studied.2.The working principle of the commonly used design method of motor——magnetic circuit method is expounded,the equivalent circuit derived by applying the method of magnetic circuit is resolved,and based on magnetic circuit method,a mini-watt permanent magnet brushless DC motor is designed,the initial structure of the motor performance parameters are calculated,including the stator laminations,rotor structure,permanent magnet size selection and size design,etc.Because the magnetic circuit method need to use the result of the empirical formula,it can't satisfy the accuracy of the design,then the finite element analysis software Ansoft is used to analysis respectively the static magnetic field and magnetic field distribution of the transient magnetic field,the emphasis was on the magnetic field of motor under no-load and load,distribution of the electromagnetic torque,the induced current,winding magnetic chains,and other important performance curve are obtained by the post-processing of the results,and the reverse voltage,inductance and loss calculation from the characteristics in permanent magnet brushless DC motor are studied based on the magnetic circuit method,which verify the feasibility of the design of permanent magnet brushless DC motor.3.The magnetic circuit structure of the built-in permanent magnet brushless DC motor can lead to a higher cogging torque,vibration and noise.Therefore,based on the demands of the design,changing the optimization of arc coefficient,changing slit width setting auxiliary tank,improving the stator core these three cogging torque inhibition projects are analyzed by finite element experiments,inhibiting effect and the characteristics of different protocols are examined and the feasibility of the cogging torque suppression is confirmed,targeting at permanent magnet brushless DC motor rotor eccentricity,the model of permanent magnet brushless DC motor rotor is eccentric processed,six groups of eccentric rotor model are set up and completely simulated,the different levels of eccentric radial air gap flux density and radial electromagnetic force are calculated by using the software calculator,the rotor eccentricity problem of the influence on permanent magnet brushless DC motor is study by comparing the results.