The Study Of Sensorless Control For PMSM Based On DSP

With the development of high performance permanent–magnet material ,electric power and electron technique,lardge scale integerated circuit and computer technique. Many scholars and researchers of home and oversea have attached importance to PMSM because of its small volume, high power density, high efficiency and power factor. In conventional motion control systems, there are many limitations by using sensors to measure the position of rotor., in this background , sensorless operation becomes very signification in the control study of PMSM. This paper focus on the vector control for PMSM,sensorless technology and sliding mode control theory, the simulation mode for PMSM is set up using Matlab/Simulink.The main content of the study as follows:The mathematic models of PMSM in several coordinates were set up. Based on the vector theory, the control system of PMSM is discussed. It was separated By transforming coordinate, both speed loop and current loop are set up.The theory of sliding mode observer is analyzed in detail. The nonlinear equations of motor driver are linearity usingαβreference frame. Real-time online estimations of motor rotor position and speed, it is sufficient that the terminal voltage and phase current of motor are known according to the motor driver. The simulation in the environment of Matlab/Simulink shows that this method is possible to estimate the rotor position. To solve the problem that it is not very perfect to estimate e.m.f with low-pass filter, the arithmetic is modified. It is innovative to put the output of low-pass filter behind the e.m.f observer which has the structure of Extended Kalman Filter. By simulating it shows that e.m.f observer filtrate much better and has good robustness.Based on the simulation, this paper introduced the hardware realization and software realization, designed the digital controlling platform of vector control based onTMS20LF2407 and Intelligent Power Model, and realized the experiment of the sensorless PMSM Vector Control System.