Research And Implementation On Intelligent Controller Of Brushless DC Motor

Brushless DC Motor (BLDCM) has many advantages such as high operation efficiency, good speed adjusting performance and non-excitation loss. Comparing with traditional DC motor, BLDCM has no relative mechanical friction, big noise, electric spark, electromagnetic interference and short service life because of no mechanical commutator. So it is used more and more widely in many high-tech fields. Especially, quick response and high precision can be achieved by using BLDCM in weapon equipment such as radar and antiaircraft artillery's servo system. Therefore, researching good BLDCM control system has been widely given attention. The control algorithm of BLDCM system directly relates to the performance of the controller. With more and more high requirements to speed adjusting performance, good result is been obtained difficultly jbecause BLDCM is a multivariable, strongly coupled and nonlinear system. Intelligent control system can solve some diffcult problems such as uncertain model and nonlinear system because it has self-learning, self-adaptive and self-organization function.According to complex control of BLDCM system, fuzzy-PID self-adaptive intelligent control is emphasized to improve static and dynamic performance and applied in this system.(1) Basic structure and operation theory of BLDCM is detailedly analyzed .Then the mathmatics model is deduced and the idea of PWM is established to adjust BLDCM's speed. Finally, the feasibility and advantage of rotor position detection by sensorless is further studied.(2) According to the idea of modularization and digitization, BLDCM's hardware system, which is made up of DSP and peripheral circuit, drive circuit and position detection circuit, is designed. At the same time, the software, which is made up of main program and interruption program is also designed.(3) Fuzzy-PID self-adaptive controller is designed to control the speed dual closed loop which has advantages both of the fuzzy logic control and routine PID.(4) Basing on MATLAB/Simulink, BLDCM's simulation system is built. By operating the simulation system, the static and dynamic performances which include starting process, the ability of carrying load and operation stability are displayed. Then it is a nalyzed that BLDCM's speed, torque, PWM, rotor's current and back-EMF response effect. Finally, the intelligent control effect is validated by comparing fuzzy-PID self-adaptive with routine PID control.