Research On Design Methods Of Brushless DC Motor Used For The Automatic Door Control System

With the increasing development of modern industry,the automatic doors are widely used nowadays.As the key element of the automatic door system,Brushless DC Motor(BLDC motor) with high power density,high reliability,fast response, facility to control and low cost is required.The power density of Brushless DC Motor is becoming higher and higher.The magnetic field distribution of motor is becoming more and more complex and the motor is with various structures,thus the traditional motor design method-magnetic circuit calculation is no longer suitable.With the rapid development of computer technology and the rise of various numerical methods,the motor design method based on electromagnetic field numerical calculation has been developed gradually.The leading investigations of this paper aim at researching the design methods of BLDC Motor.Firstly,equivalent magnetic circuit method and electromagnetic field FEA(Finite Element Analysis) method are compared,and their merits and demerits are analyzed separately.Then a design method combining field and circuit which is suitable to Brushless DC Motor is educed.The paper analyzes the DC-motor's similar design features and tries to make a reasonable electromagnetism design base on the features of Brushless DC Motor.The paper analyzes DC-motor's design features and tries to make a reasonable electromagnetism design base on the features of BLDC Motor.Secondly,MATLAB language was used to turn the manual calculation into the computer programs.Methods of image interpolation and curve fit were used to make the design process more convenient,faster and to make the best of computer's advantages.The CAD program can be used to optimize the electromagnetism design schemes rapidly and improve the design precision.Finally,the magnetic circuit blue print is modified and improved using the FEA software Maxwell.The experiment data of prototype machine and the result of the design using the combining field and circuit method was compared and analyzed.The comparison proved the superiority of the method used in the electromagnetic design of Brushless DC Motor.