| Permanent magnet brushless DC motors （BLDCM） is composed of the statorwindings and the rotor permanent magnet and has no commutation device and its controlcharacteristic is similar to the brushed DC motor. Due to its many merits such as largetorque, high efficiency, high speed, the advantages of simple control and easy maintenance,etc., and along with the development of power electronic technology, permanent magneticmaterials, digital electronic technology and new control theory, permanent magnetbrushless DC motor shows broad application prospects in the field of high performanceservo drive.Firstly, thesis researches into the body of permanent magnet brushless DC motor andanalyzes its structure and working principle, and carries on the mathematical modeling.This paper expounds the principle of the S-function motor model and builds the controlsystem for simulation in Matlab/Simulink platform, establishing the theory basis of thepermanent magnet brushless DC motor control strategy research and controller design..Based on stepper control theory, the control characteristics of permanent magnetbrushless DC motor is studied. Stepper control strategy of discrete current is put forwardwhich is suitable for motion control of permanent magnet brushless DC motor. Severaltypical incremental motion modes of motor control and optimization are studied, and thedynamic characteristics of discrete stator current control system are analyzed. That breaksthe strict boundaries of traditional incremental motion control ideas, continuous anddiscrete, speed and position, rotation and step.Stepper control theory makes the stator androtor magnetic field movement as the main control target， organically combiningincremental control and motion control to reduce the torque ripple of permanent magnetbrushless DC motor, make it to the direction of large capacity, high efficiency and highprecision.The permanent magnet brushless DC motor control system based on dsPIC isresearched and designed. The dsPIC30F6010A is the core of the digital controller, and thepower main circuit and various protection circuits with IRS2336D as intelligent drivermodule are built, and photoelectric encoder detection circuit and current detection circuitand other system detection circuits are set up, and communication circuit with the uppermachine is designed. In addition, considering the practical application of the circuits, theisolation control power and the extra speed and position control circuit are designed, etc.Ultimately the stepper control of permanent magnet brushless DC motor is realized.Analysis and experiments show that the stepper control strategy has good controlperformance. The system embraces good speed and position control performance and can effectively reduce torque ripple, which provides a theoretical basis and practicalengineering method for the wide range of applications of permanent magnet brushless DCmotors. |
