Research And Design Of High Voltage Sensorless Brushless DC Motor Controller

Brushless DC motors are widely used in various industries due to their excellent characteristics.In recent years,the emergence and development of new technologies and new industries such as new energy automobile industry,robot technology,and aerospace technology can see the appearance of brushless DC motors.There is a growing social demand for brushless DC motors.It is foreseeable that as the related industries become more mature,brushless DC motors will have more and more broad prospects.This paper designs a position sensorless brushless DC motor controller for an industrial electric pick-up device.This paper will carry out in-depth research on the sensorless brushless DC motor control based on the actual controller design,and design a prototype.Firstly,it introduces the development history of brushless DC motor and its social needs,and the significance of its research.The important issues of brushless DC motor control research are introduced.The basic structure of the brushless DC motor is described in detail.The basic principle of the motor operation is described.The mathematical model of the motor is obtained by mathematical analysis combined with the physical characteristics of the motor,which lays a foundation for the subsequent chapter analysis.Secondly,the most widely used counter electromotive force method is selected in the control strategy for key analysis.The influence of the filter in different control modes of the back electromotive force method is explained.In the back electromotive force method,the DC bus midpoint voltage Comparison method,the virtual neutral point method,the calculation method,and the falling edge A/D sampling method are carefully analyzed and compared.The principle of the widely used three-stage starting method is described in detail,and the starting principle is analyzed By mathematical methods.The simulation analysis of the brushless DC motor and its control system was carried out by using MATLAB simulation softwareFinally,based on the selection of the falling edge A/D sampling detection method,the motor controller circuit is designed and completed,and the functions and implementation methods of each module are described in detail.Clever use of the amplifier's cut-off function,filtering higher voltage signals,so that the microcontroller can detect the back-EMF zero-crossing with A/D.A circuit board of the brushless DC motor controller was drawn,and a prototype of the controller was fabricated.At the same time,the implementation details of each function of the software are introduced in detail,and the problems that may be encountered in the actual development process are carefully explained.The actual implementation of the software implementation of the startup problem is described.The speed control implementation is optimized.A description of the problem of commutation of the motor is given.The software was written and tested on the basis of this prototype.