| Brushless DC motor has many advantages,such as good speed controling performance,simple structure,high efficiency and high reliability.It also keeps the excellent mechanical characteristics of DC motor,so it is widely used in the various branches of electric drive and position servo.But the motor in the traditional brushless DC motor's control system has cogging torque and system torque ripple caused by the nonlinear power devices in the inverter,along with vibration and noise problems,which will shorten the service life of the motor.With the rapid development of modern industry,the requirements for the suppression of torque ripple are increasing.Therefore,the torque ripple reduction of motor is of great significance.Based on the traditional PID control method,the fuzzy PID controller is designed,which adopting the double loop control of space vector and carring out the simulation study that is based on the Matlab/Simulink platform.Compared with the traditional PID simulation,the fuzzy PID controller has better dynamic performance and it can reduce the torque ripple.Aiming at the complex structure and low reliability of position sensor,the back electromotive force method is applied to accurately evaluate the rotor position of the motor when the motor runs stably.And the simulation study results show the effectiveness and reliability of this method.For the starting of the motor,the traditional pulse vibration high frequency voltage injection method is optimized,and the speed and rotor positions are accurately estimated.Finally,through the hardware and software design,a motor control system with DSP28035 as the core processor is built,which realizing the vector control of Brushless DC motor under the sensorless condition.Compared with the traditional PID controller,the experimental results show that the fuzzy PID controller can maintain stable operation under the condition of both no load and load.At the same time,it can weaken the torque ripple in a certain extent. |
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