Study And Design On A Control System Of Sensorless Brushless Dc Motor Based On Dsp

Brushless DC motor (BLDCM) is a brand-new mechatronic motor based on the development of power electronics and the advent of new permanent magnetic material. It has been widely used in industrial applications because the advantages of simple structure, high reliability, high power density, high efficiency and good performance, etc. Moreover, sensorless control not only overcomes a lot of disadvantages generated by the sensor, but also expands the application range of brushless DC motor. At present, sensorless control is one of main research directions of control technique for brushless DC Motor. This paper study the design of sensorless control system of BLDCM.Firstly, this paper gives a deep research on basic structure, working principles, gives the mathematical model of BLDCM, and discusses the method of BLDCM rotor position detection which test the back-EMF signal and the plan of the double closed-loop control system is established based on this.Secondly, taking TMS320LF2407A DSP as the core,, hardware electric circuit of the system is designed combined with driver chip IR2130. Simultaneously the position detecting circuit, the inverter circuit as well as the essential protection circuit is designed. The software of the system includes: initialization program of DSP, open-loop commutation start-up program, the phase switching program and soon, which is used to realize each kind of function request of control system.Lastly, Matlab/Simulink is used to conduct the simulation study of BLDCM and its control system. The simulation model of BLDCM is built from the viewpoint of modularization, in which the overall system is separated into multiple isolated functional modules. Simulation results indicate that the rationality of the control system and proved the control system works well as it was expected.