Research And Design Of Experimental System For BLDCM Based On DSP

At present, with the rapid development of the power electronics, control theory and algorithms to achieve various kinds of software in microprocessor technology, detection technology and digital signal processing technology, motor control technology is also facing unprecedented opportunities and challenges. These technologies and theories gradually infiltrate into various motor motion control system, greatly increasing the dynamic and static performance of electric drive system. Brushless DC motor not only has a series of AC motors' advantages, such as simple in structure, reliable operation, convenience to maintain and so on, but also has a lot of DC motors' traits of high operating efficiency, like no excitation loss, excellent speed adjusting performance etc. Particularly, our country is rich in rare earth materials, providing the exceptional conditions for the development of brushless DC motor. In this paper, an experimental system based on DSP is designed for permanent magnet brushless DC motor (BLDCM).At the beginning of this paper, the development and status of BLDCM and its control technologies are introduced, the basic structure, the principle and mathematical model of BLDCM are also illustrated. Then this paper presents the control technologies and strategies about BLDCM, on the basis of the analysis and comparison of the advantages and disadvantages of various control methods, advanced fuzzy control theory is applied to the traditional PID controller, it can effectively overcome some control problems such as nonlinear, time-varying parameters and model uncertainty caused by brushless DC motor, and it is superior to the control performance of the PID controller. Fuzzy-PID control system has been modeled in detail according to the characteristics of fuzzy-PID controller and mathematical model of BLDCM in powerful MATLAB/SIMULINK, then simulation is carried out at the end of charpter 3.In the part of hardware design, an overall structure is introduced and an overall strategy of hardware circuit design is given, which includes peripheral circuits of DSP, signal processing circuit, power driver circuit and so on, the position signal detection circuit, bus current detection circuit and fault detection logic circuit are also designed. For all the close cooperation among the circuits, careful consideration is carried out for hardware design based on actual project.And the software of control system is given which includes client and PC program. Client program includes main program design and associated interrupt service subroutine, and a flow chart is drew based on design idea of the modular structure; In the procedures design of PC, the PC serial port is focused on for the opening of settings, I/O operation and data processing after receiving information in the windows 32 system, timely and accurate data transmission is realized through serial communications between PC and client.In the end of this paper, the experimental system is verified validity, correctness and feasibility by debugging and analyzing the experimental result, and stable hardware platform and smooth software operation meet the design requirements.