Study On Control Of Permanent Magnet Synchronous Motor For Main-spindle Direct Drive System Based On TMS320F2812

The main work of this paper is to design and develop a sort of software and hardware platform of the PMSM vector control system used in the direct drive system of the machine tool spindle. A lot of experiments and simulation are deeply studied based on this platform, and the results prove the feasibility of the design.Firstly, the theory of coordinate transformation is elaborated fully, and the mathematical model of PMSM at different coordinates is deduced based on the configuration of PMSM. Simultaneously, the vector control theory of PMSM and i_d = 0 control strategy are fatherly studied. In addition, the basic principle and characteristics of the space vector pulse width modulation (SVPWM) is studied in detail.Secondly, the simulation model of the motor system is set up through the MATLAB software. The simulation system consists of the PMSM model, the power module model, the testing model, the coordinate transformation model, the adjusting model of current and speed, the SVPWM model and so on. The simulation results show the feasibility that SVPWM and vector control technology are utilized in the system, and in the meantime provides a theoretical basis for the system platform design.Thirdly, in order to improve the dynamic and static characteristics of the system, the software and hardware of the full-digital PMSM vector control system is designed based on the DSP TMS320F2812. The part of hardware includes current detector, velocity detector, display circuit, driving circuit, main circuit and protecting circuit, etc. And system software is realized in DSP, and the i_d = 0 vector control method is adopted to realize the decoupling control of PMSM. The classic PI control method is used in the speed and current loop, and the SVPWM strategy is used in the inverter. In the meantime, the routine flow charts are given, such as the system initialization subprogram, the current and velocity adjusting subprogram, the SVPWM realization subprogram and the drive protection subprogram, etc.Finally, a great deal of further studies is done based on this experiment platform, and experiment waveforms are analyzed deeply. The results indicate that the system has many great advantages such as fast response, running stability and smoothness at the low speed, and the ability to reject interference, which can meet the demand of the direct drive system of the machine tool spindle.