Research On Servo Control System Of PMSM Based On DSP

PMSM AC servo system is a kind of new-style AC servo system which consists of PMSM, modern electronical technique and control technique. Because of its good performance, it has become one of research hotspots in electric drive of the time. With developments of power converters technology and high performance microprocessors, servo system is gradully developing towards full digital implementation of the controllers. Full digital AC servo system is highly reliable, and it is excellently flexible to implement new control strategies without ameliorating system hardware.The background of this thesis is a cooperation item with Baosteel Group Inc. The title of the item is"Moving stage for rolling steel testing". In this thesis, based on a digital signal processor TMS320LF2407, a full digital controller for PMSM is studied and designed.Firstly, the background, development and future prospect of servo system is described, the mathematics model of PMSM is analyzed, the vector control of PMSM and space vector PWM is studied. Then the controller of position, speed and current are discussed, the PI position controller, PI speed controller and PI current controller are designed according to the requirement of Baosteel Group Inc. PMSM AC servo system is set up and DSP controller is designed, the corresponding software is developed, their structure and function are described in detail. Specially, two methods of initial rotor position detection for PMSM using incremental encoder are discussed. The implementation of M/T velocity detection based on DSP is given, and a method of velocity detection based on software PLL is introduced to improve the detection accuracy. Finally, experiment was performed based on the actual system. The electricity wave form and the motor position were recorded and analyzed when the system was run. The experimental results show that the servo control system designed in this thesis is satisfied to the static and dynamic performance, has good accuracy.As a result of this research, the system has been successfully used to the"Moving stage for rolling steel testing".