Research On The Sensorless Control Of PMSM Based On DSP

Abstract：Permanent magnet synchronous motor (PMSM) is a autocontrol frequencyconversion ac motor, the control of it depends on the rotor position and speedinformation. In a traditional PMSM control system, in order to obtain the rotorinformation a mechanical sensor is usually installed in the rotor shaft. However, theusing of mechanical sensor not only increases the cost and complexity of the system,but also decreases the system robustness. Because of that the sensorless controltechnology is invented in motor control field and received more and more attention.Under this background, this paper introduces the sensorless control technology andperforms some experiments in detail.Firstly, mathematical models of PMSM are set up in different coordinate systemand the vector control scheme which is used extensively in ac motor control isanalysed. Combine with the space vector pulse width modulation (SVPWM) thethree-closed loop-current, speed and position control system of PMSM is built.Secondly, various kinds of estimation methods about rotor information areintroduced and analyzed, which are used extensively in sensorless control system ofPMSM. Based on the thought of salient pole tracking, this paper studied theapplication of the rotating high frequency signal injection methods in detail. Inconsideration of the experimental requirements of this investigation, the simulationmodel of PMSM is established by the means of MATLAB/Simulink based onhigh-frequency voltage signal injection method. The simulation shows that thesimulation system not only possesses short response time, but also has simpleconfiguration and good dynamic and steady performance.Finally, the sensorless vector control system of inset-type PMSM is built, whichdepended on the increasingly mature of power electronic technology and digitalsignal processing technology. Digital signal processor (DSP) TMS320F2812isserved as main control chip in this system and the design of controlling and drivingcircuits are connected to the DSP. Software design in this system is fulfilled withCCS3.3, and some key modules which are closely associated with the precision ofPMSM are designed optimally. The results manifested that the estimation system, which is ground on the high-frequency voltage signal injection method, is capable ofprecisely estimating the rotor speed and position information of PMSM. Thissensorless vector control system of PMSM in this paper is not sensitive to thechanges of motor parameters and external interference, and it possesses high stabilityand strong robustness.