| Permanent magnet brushless DC motor(PMBLDCM)has the clear advantages of rapidity, controllability, reliability, small, light in weight, energy saving, high efficiency, survivability in environment, economical efficiency, simpler control system compared with the induction motor, and so on. Therefore, PMBLDCM is widely used in every field of national economy at present, such as Aero-Space, industrial robot, medical appliance, instruments and meters, chemical engineering, light textile and household appliance, etc.First of all, the research situaiton and development trend of PMBLDCM control system is introduced. Also the structure of the motor is introduced, and the operational principle is analyzed. Based on traditional mathematical model, a model which has more utility value is derived, to help the new control strategies applicable to PMBLDCM.Secondly, direct torque control(DTC) fundamental principle is applied to PMBLDCM, in the hope of suppressing torque ripple. Contrastively analyzed the control strategies of PMSM, the principle, mathematical model and control system structure of the PMBLDCM DTC are all discussed, and then a control scheme of the PMBLDCM DTC system is given, and also the simulation of the scheme is done. The simulation results make clear that the scheme suppresses the torque ripple effectively.Finally, a kind of accomplished scheme 3KW PMBLDCM DTC system is designed.The hardware circuits and software design are analyzed detailedly. The hardware circuits consist of DSP governer circuit, power circuit, high precision position & speed detection circuit with resolver TS2225N12E102 and RDC chip AU6802N1, high power IGBT module drive circuit and other related circuits. Based on the theory of the DTC, the overall control software is designed, and then parts of the functional module is debugged completely. Considering the working environment of the system, the thermal calculation is done, the choise of radiator is discussed, the electromagnetic compatibility (EMC) of the control system is analyzed. |
