Research On The Controller Of Sensorless Brushless DC Motor

The brushless DC motor which is widely used in home appliances, transportation,medical equipment, CNC machine tools and robots has some typical advantages:small size, light weight, high efficiency, good speed regulation performance, no commutation spark, no excitation loss and so on.With the development of modern industry, the performance of brushless DC motor system is highly demanded. Predictably, with the permanent magnetic materials and power electronic devices further price reduction, research on brushless DC motor drive theory is going deep and the application prospects of brushless DC motor will be wider than before.Based on the sensorless brushless dc motor(BLDCM) control system, this article introduces the application prospect of brushless dc motor, the research direction,compares the non-inductive brushless dc motor with position sensor brushless dc motor, the advantages and disadvantages of the non-inductive mathematical model of brushless dc motor. The working principle and its operation mode are comprehensively analyzed in the research. At the same time, the start of the motor,position detection technology, the closed-loop control of motor speed are analyzed emphatically, which provides a theoretical basis for motor control scheme.This paper provides a complete hardware circuit of the control system design and software control using the C language. The motor startup scheme adopts a three-step startup, and the sensorless control circuit is based on the voltage across the counter electromotive force of zero point detection circuit. A circuit driver chip IR2110 is using as the motor drive. A closed-loop PID control algorithm is used as the control method to improve the speed performance of the system, and the control chip uses the TM4C123GH6 PM from Texas instruments Tiva TMC series. Taking the advantage of the arithmetic core processing power and rich peripheral, the entire system eliminates the previous complex hardware circuit, adopt a more rational structure to successfully implements most of the functionality of the software system,which improves the reliability.