Study On Brushless Permanent Magnet Coreless Motor And Controller

With the rapid development of power electronics and microelectronics technology,brushless motor is widely used in high-performance control systems.In order to improve the performance of motor,people strive as much as possible to explore new motor,continuously.Coreless motor,a distinctive type of micro-motors with coreless armature which broken the structure of traditional core motor,is provided with outstanding energy efficiency and control characteristics.It will be one of direction of the motor development in future.Because of the improvement of manufacturing technology,its performance is enhanced.Nowadays,coreless motor maturely requested in the products of military,aerospace and aviation,and other high-tech field,at the same time,it is also widely applied in many products daily necessities,industrial production and other civilian areas.A novel design method of the brushless PM coreless motor,integrating the method of magnetic circuit with the finite element analysis is proposed,in this paper.Basing on the finite element analysis,the structure of motor is optimized to make it run more smoothly with smaller torque ripple.Meanwhile,so as to test the performance of the motor,it has designed a low-cost,fast response SPWM drive with Hall position sensor.The thesis mainly research performed as follows:Firstly,the overall design scheme of brushless coreless motor is proposed,after it introduced the structure and principle of brushless coreless motor.Then the process and principles of magnetic circuit calculation and the method of choosing the gap length,the thickness of the permanent magnet and other parameters is expounded.Based on the formula of motor,the major parameters of the motor size and winding are calculated,to achieve the brushless motor coreless preliminary design.Secondly,two-dimensional FEM model of the coreless motor is established and the static and dynamic magnetic field analysis is completed,to compare the impact of the motor armature reaction on the air-gap magnetic field on load with the one on no-load.And then it optimizes the air gap magnetic field through parametric analysis.Finally,to determine the motor nominal working point the operating characteristics of the motor is analyzed in the way of electromagnetic analyzing and calculating.Thirdly,after choosing the control strategy of brushless coreless motor,The speed controller of the fuzzy PI and the current controller of PID is designed in the method of the engineering.Then it introduces the method of SPWM and the estimation algorithm of speed and position based on the Hall sensor in motor.With the MATLAB simulation,the performance of speed commanding and the deviation of the speed and position calculating algorithm in different orders is analyzed.Finally,the SPWM speed controller of coreless brushless motor is implemented through the live communication between MCU and SPWM signal generator.Fourthly,with Manufacturing and mounting of the brushless coreless motor,the basic parameters is detected to prove that the method of brushless coreless motor design is correct.By detecting the output of controller such as Hall waveforms,three-phase voltage waveforms and the speed of motor,the performance of speed commanding and the commutation of motor is tested and verified.