Sensorless Control Of Permanent Magnet Synchronous Motor Based On High Frequency Current Injection Method

Permanent Magnet Synchronous Motor(PMSM)has a unique advantage in the field of industrial automation for its advantages of small moment of inertia,simple structure,high efficiency,etc.However,the defects due to the installation of mechanical position sensors used to obtain the rotor position and speed signals in Traditional motor control system.Although it has brought benefits,but it also brings many disadvantages such as complex installation,high cost and so on,which limit the systems' application areas.Therefore,the technology of sensorless control has been the focus of the industrial and research.In order to prove the performance of the Surface Mounted Permanent Magnet Synchronous Motor(SPMSM)control under low and zero speed without a position sensor,the method that pulsating high-frequency current injection is studied in this paper,and different kinds of digital filters are designed either.At first,theory and current situation of sensorless control technology has been classified and overviewed based on the domestic and foreign literatures.An ordinary list of the sensorless control methods is proposed in this paper either.Secondly,the PMSM vector control system model is constructed using MATLAB/Simulink and both the systems with or without position sensor are simulated.Then,the method that pulsating high-frequency current injection is deeply studied after studying the traditional several high-frequency signal injection methods,the principle of magnetic saturated saliency of SPMSM is analyzed and the digital filters are designed.The preliminary comparison of the effect of IIR and FIR digital filters on the performance of control system,drawing the conclusions that the latter has better filtering effect.Finally,a hardware platform for PMSM sensorless control based on MC56F8257 with a 750W SPMSM is designed and constructed,with which the software system based on sensorless control algorithm is designed and debugged.The waveforms of motor starting,load/unload load and stable operation are given in this paper,which verify the correctness and feasibility of article content.