Research And Implementation Of High Speed Brushless DC Motor Without Position Sensor Control Technology

The brushless DC motor( BLDC), with the electrical circuit to replace the mechanical brush and the commutator,is one of the most high effective motor currently。And the use of no position sensor control technology,not only can overcome many shortcomings of the position sensor,but also to improve the dynamic characteristics of the motor and the safe and stable operation ability,reduce vibration and noise,etc。Therefore,sensorless control method of BLDC motor has been darwing more and more attention, and is on the way to functionalism。At present,The speed of the most objects that the sensorless controller of BLDC motor controlled is thousands of revolutions per minute on the market。However,the motor speed is required to reach tens of thousands of revolutions per minute in some industrial,like medical、household appliances and so on。Under the circumstances,on the one hand the realization of the control method has faced higher demands,on the other hand manufacturers have strict request for the cost of the controller。Although we can realizes the control of the motor with high-end chips,but market prospects and competitiveness of products is limited by the expensive chips that will lead to the sharp rise in the cost。To above-mentioned problem,high performance BLDC motor control system with sensorless controller will be researched in this paper。It is a system that based on low-cost STM8 chip as the core and a high speed BLDC motor as control object。Programs about sensorless brushless DC motor control system will be made in this paper after the analysis of mathematical model of brushless dc motor,the basic working principle, start method,and Back EMF Detection Method。The hardware circuit and software programming of control system have been completed。Hardware circuit contains power supply、power driver circuit、chip peripheral circuit、the zero examination circuit、current detection circuit,etc。Software programming mainly includes the main program、the initialization、subroutines、interrupt nesting procedure,etc。Finally,the experimental platform was studied,the motor starting, speeding up and running as well as the speed adjustment was tested。The experimental results show that the design is reasonable and high performance-price ratio,the hardware cost is low,the speed control range is wide,and fully reflects the superiority of the sensorless brushless DC motor especially for the control of high speed brushless DC motor。...