Sensorless Starting Operation Control Strategy Of High-speed Permanent Magnet Synchronous Motor Based On High-frequency Signal Injection

Permanent Magnet Synchronous Motor(PMSM)has the advantages of small size,high efficiency,high power factor and low failure rate,and is widely used in industry and the market.One is the sensor method and the other is the sensorless method,where the sensor method causes high system costs and the sensor itself has a service life,so the sensorless method is to a certain extent better than the sensor method.At present,the sensorless control technology of PMSM in the medium and high speed section is relatively mature,however,the rotor position detection is not accurate enough in the starting and low speed,especially in the high speed,the algorithm is complicated and the error is large,in order to better study the high speed section of PMSM,therefore,the starting,low speed and high speed conditions of PMSM are studied.The main work of this article includes:(1)The structure and classification of PMSM are analyzed,and the electromagnetism model of PMSM is created.On this basis,the vector control method and space vector pulse width modulation method of PMSM are studied,and the vector control scheme of high-speed PMSM in this thesis is determined.(2)During motor starting,a new filtering method is proposed instead of the low-pass filter of the system,in order to address the problem of the phase shift generated in the filtering link of the rotor initial position identification method after the traditional high-frequency signal injection,which affects the accuracy of the rotor initial position;to study the individual rotor positions that fail to estimate,and to propose a method that can estimate the PMSM rotor initial position with a high success rate,and finally the correctness of the proposed method is experimentally verified,in order to The final experiments verify the correctness of the proposed method and pave the way for studying the subsequent operation of the PMSM.(3)At low motor speeds,the conventional modulation signal used in the traditional pulsation HF injection method causes a change in high frequency impedance in the presence of motor stator resistance,resulting in a disturbance in the PMSM system at low speeds.At the same time,a new method and structure is added at the end of the new pulsed high-frequency injection system to further filter out the harmonic interference signal containing the rotor position information term,and the experimental results show that the method is more accurate in detecting the rotor position information under low-speed operating conditions and makes the detection system more responsive.(4)In the motor at high speed,in order to solve the problems of complex algorithm,large calculation volume and large error in the estimated rotor position,a new Luenberger observer algorithm is proposed to change the feedback gain according to the motor speed to avoid the high speed affecting the rotor position estimation accuracy;a phase locked loop based on adaptive fuzzy PI control is established and the PI parameters of the phase locked loop are self-tuned to solve the problem of high speed PMSM speed The proposed method can accurately detect the rotor position information,rotational speed and ensure the stability of the system at high speed,as demonstrated by the experiments and the physical simulation of the upper computer.