Study On The Hybrid Sensorless Control Of Permanent Magnet Synchronous Motor At The Full Speed Range

Permanent Magnet Synchronous Motor(PMSM)is widely used in various industries due to such advantages as high efficiency,high power density,excellent control performance and simple structure.The position sensorless control technology eliminates the need for the traditional position sensor,which can reduce the system cost and improve the reliability and stability of the system under rigorous operating conditions efficiently.In this paper,the Inner-mounted Permanent Magnet Synchronous Motor(IPMSM)is taken as the research object,the position sensorless control technology is taken as the research core,the performance of the motor at the full speed range is taken as the research goal,and simulation with MATLAB/SIMULINK and experiment are used as verification means,and the main work of this paper is as follows:Firstly,the research status of motor position sensorless control technology is introduced,which leads to the problem that single method cannot be applied at the full speed range.The research status of motor parameter identification is introduced,which leads to the importance of parameter identification at the full speed range.Secondly,the fundamental and high frequency models of PMSM are established in different coordinates.The simulation model based on the i_d=0 control strategy is built and verified.The models of the rotating and pulsating high frequency voltage signal injection(HFI)method are deduced in detail,by contrast the pulsating high frequency voltage signal injection method is selected for verification.Then the mathematical model based on model reference adaptive method(MRAS)is proposed and the stability of the system is proved.The effect of motor parameters on estimation performance is studied.An improved MRAS based on Recursive Least Square(RLS)with parameter identification is proposed.Q-axis inductance and permanent magnet flux are identified and updated on-line in view of their strong effects on estimation performance.The performance of PMSM based on MRAS is evaluated at different speed and parameters based on simulation.Finally,the performance of single position sensorless control method at high and low speed respectively are compared and the causes of difference performance are analyzed.Based on weighting function,a hybrid position sensorless control method at the full speed range is proposed and performance of proposed method is analyzed by simulation.The performance of the hybrid control method at the full speed range is simulated and analyzed.The experimental platform based on the hybrid position sensorless control system is built.The accuracy of the signal acquisition of rotary transformer and the rationality of the pulsed high frequency injection method are analyzed and verified.Then compare the performance of the hybrid control method with the single method at the full speed range,and the dynamic response experiment within a given wide speed band is conducted.The results show that the relative error can be controlled under 10%,it's much lower than the single position sensorless control method,which can conclude that the proposed hybrid position sensorless control method at the full speed range is feasible.