Magnetic Field Optimization And Intelligent Control Design Of The Novel Permanent Magnet Brushless Dc Motor

In the process of petroleum exploitation and transportation pipeline construction in petrochemical industry,due to remote location and poor ground communication,a large number of emergency data can not be processed in time,which affects work efficiency.Satellite communication technology has become its solution because of its wide coverage,long communication distance and high real-time performance.The emergence of commercial micro nano satellites provides the possibility for the technology to be widely used in civil fields.The accuracy of satellite communication technology is directly affected by the satellite attitude control accuracy.Therefore,as an important driving system of satellite,the mechanical performance and speed control accuracy of permanent magnet brushless DC motor are the key to the attitude control accuracy of the whole satellite.In this paper,by analyzing the current research status of the current permanent magnet brushless DC motor structure and motor control method for flywheels at home and abroad,it is found that the existing permanent magnet brushless DC motors generally have low effective air gap flux density,large interference flux density and serious flux leakage.In view of the above problems,the novel permanent magnet brushless DC motor with inner and outer double-turn permanent magnet structure is proposed.According to the structure of the novel permanent magnet brushless DC motor and based on the analysis of electromagnetic characteristics,a highprecision speed control system is designed in view of the defect of insufficient speed control accuracy of the traditional PID control system.Based on the structure and electromagnetic field principle of the novel permanent magnet brushless DC motor,the air gap magnetic field mathematical models of the traditional permanent magnet brushless DC motor and the novel permanent magnet brushless DC motor are deduced by using the equivalent surface current method,and the motor structure is optimized.Based on the analysis of the magnetic circuits of the two motors,the air gap magnetic density is compared and analyzed by the finite element method.The simulation results show that the novel permanent magnet brushless DC motor has larger effective air gap flux density,smaller interference flux density,wider air gap flat top width and lower magnetic leakage,and has good mechanical properties.According to the structural characteristics of the novel permanent magnet brushless DC motor,its working principle is analyzed,and its dynamic characteristic mathematical model is deduced.In order to realize the high-precision control of the novel motor,a fuzzy PID control system is built based on the principles of PID control and fuzzy control.At the same time,the idea of variable universe is introduced to design a variable universe fuzzy PID controller.Firstly,the control performance of the two motors is compared by MATLAB/Simulink software.The results show that the novel permanent magnet brushless DC motor has the advantages of fast response,high speed stability accuracy and low torque ripple;Then,three control systems of the novel permanent magnet brushless DC motor are compared,namely PID control system,fuzzy PID control system and variable universe fuzzy PID control system.The results show that compared with the traditional PID control system,fuzzy PID control system and variable universe fuzzy PID control system have the advantages of fast response,low overshoot,stable dynamic performance and superior speed regulation performance,among them,fuzzy PID control system has more advantages.The novel permanent magnet brushless DC motor is obtained through processing,and the air gap flux density measurement experimental platform and motor control experimental platform are built respectively for experimental verification.According to the results,the novel permanent magnet brushless DC motor has large effective air gap magnetic density,small interference magnetic density and low magnetic leakage,and has superior mechanical structure;The fuzzy PID control system has superior performance and is very suitable for the speed control of novel permanent magnet brushless DC motor,which provides a new scheme for highprecision attitude control of satellite.