Research On The Control System Of PMSM Based On DSP And Sliding Mode Observer

In the past,most of the control system need to install a position sensor in the rotor shaft to get the rotor position and speed signal, the existence of these mechanical sensors increase the size of motor and the cost of the system,decreasing the reliability. Therefore, sensorless control technology has attracted more and more attention by scholars. Sensorless control is by measuring the motor current, voltage and other measurable physical quantity to estimate the position and speed through special algorithm.Sliding mode control, as a special nonlinear control strategy, has the characteristic of fast response, good robustness, easy design. So, this article will introduce the sliding mode control to PMSM control system, research and implementation of sensorless vector control of permanent magnet synchronous motor drive system.Firstly,this paper compares several methods of rotor position detection of the sensorless permanent magnet synchronous motor,among them,we select a kind of rotor position estimation based on sliding mode observer,which has advantage of simple control algorithm and easy implementation of engineering application.Secondly, the theory of sliding mode control is studied in depth. Then proposed the design steps of sliding mode controller,the causes of the chattering phenomenon are analyzed in detail,and the main methods to eliminate chattering are elaborated.Thirdly,on the basis of analyzing the mathematical model and vector control theory of PMSM,proposed a method based on SMO to estimate the rotor position, using Matlab/Simulink to built each simulation module,then according to the principle of SVPWM,the system model of PMSM is established. The simulation results show that the control method is feasible,having good robustness.Finally,the software and hardware of control system based on TMS320LF2407 are studied.The hardware design includes circuit of stator current detection, circuit of bus voltage detection, isolated drive circuit and protection circuit. In terms of software, integrated development environment is introduced,and then described the algorithm and flow chart of each modules.