Research On Sensorles Brushless DC Motor Control System Based On TMS320F2812

Position sensor in the brushless DC motor (BLDCM) applications in industry have many disadvantages. On the base of analysis of the common sensorless control techniques, this paper pays more attention to basic principle and method of the detection of rotor position through back-EMF. With the rapid increasing chip performance and lower chip prices, all-digital control system has become the development direction of industrial control. So a sensorless brushless DC motor (BLDCM) control system based on TMS320F2812 is studied in this article.Mathematical model of BLDCM, the basic working principle, speed control method and the back-EMF voltage detection method is analyzed in this paper. And a sensorless BLDCM control system simulation platform is established in MATLAB. The platform can be applied to validate the system control algorithms and support experimental platform for the actual control system design and debugging. The simulation results show that two closed-loop PI sensorless BLDCM control system can achieve good speed performance.According to the control system scheme, the control system hardware circuit is designed, which includes power driver circuit and the rotor position detection circuit. Drive circuit is built from application IR21367 power integrated driver and based on the requirements and characteristics of control chip. By detecting the back-EMF zero crossing to achieve sensorless control is rotor position signal detection circuit design theory. Hardware reliability is verified by experiment.The control system software is designed in C language. It is modular programming. So the designed control system software has good versatility and scalability. And then Combined with control system hardware, the entire control system is experimentally studied and export experimental results. The experimental results indicate that the designed control system can run stable with good speed performance. Meanwhile, compared to control with a position sensor, BLDCM sensorless control of superiority is reflected.