Study On Improved Vector Control System For Brushless DC Motor

The invention of Brushless dc motor is owing to the rapid development of power electronic devices and the emergence of permanent magnet in our life. As the replacement of common dc motor mechanical commutator, electronic commutator can solve some problems brought by traditional dc motor, and it integrate the advantages the same as dc motor and ac motor, which prolongs the life of the motor and improves work efficiency. The brushless dc motor can achieve the same equivalent effect as ordinary motor, when using appropriate control strategy. So, the brushless dc motor has high research value.Firstly, this paper first introduces the structure, its working principle and the maths model of coordinate transformation of the brushless dc motor. Based on the principle of vector control, feed-forward decoupling compensation method is proposed to improve the deficiency of traditional vector control. What is discussed in this paper is the design of the vector control system of the brushless dc motor.Secondly, brushless dc motor vector control system was built in MATLAB7.0/SIMULINK. The paper designed the brushless motor vector control system based on excitation current component with speed loop and current loop of the double closed loop PI control which verifies the feasibility of the proposed vector control system.Then, the paper used MCK2812 motion control development platform, which was produced by TECHNOSOFT; TMS320F2812 chip from T1 company was used as control circuit; power driver board USES is IR2132 MOSFET inverter. In this paper, the main content is the development of system software program, which was written in CCS3.3 development environment, mainly includes coordinate transform, sampling calculation of current, speed calculation, PI control algorithm, the generation of SVPWM waveform, etc. Then the target is to realize the frequency control of the brushless dc motor.Finally, a hardware system is built, and the program has been debugged online, and it realizes the control of motor in the DSPMOT software. The experiment results proved the feasibility of this program and vector control system. Furthermore this paper is summarized and prospected as well.