Research On The Position-sensorless Control Technology Of Pmsm In Full Speed Range

Permanent magnet synchronous motor is widely used in household appliances,industrial control,electric vehicles,aerospace and other fields because of its high energy/power density,low speed start performance,strong overload capacity and high efficiency.In order to avoid the use of mechanical speed/position sensor and improve the reliability of the system,this paper studies the position sensorless control method of PMSM in full speed range.After the comparison of the existing position sensorless control methods,the position sensorless vector control system of PMSM combined with the pulsating high frequency voltage injection method and the model reference adaptive system(MRAS)is designed in this paper.Mainly completed the following work:Firstly,the mathematical model of PMSM is established.Based on the vector control strategy,the pulsating high frequency voltage injection method position sensorless control method of PMSM is studied.The system is simplified by removing bandpass filter from the signal processing.The problem of "special position" and the inaccuracy of d axis judgment in the process of initial position estimation of rotor are solved.So the position angle estimation of PMSM at zero and low speed is realized.Secondly,the effects of non-ideal factors(non-ideal factors of the inverter,stator resistance,cross-coupling terms)on rotor position estimation of pulsating high frequency voltage injection are analyzed.It is concluded that non-ideal factors and stator resistance have little effect on the rotor position estimation.For a motor,the higher the rotational speed,the larger the rotor position estimation error.For the motors with different saliency,the estimation error of the rotor with low saliency is high at the same speed.Thirdly,the sensorless control algorithm based on MRAS is studied and the dead zone compensation is carried out considering the non-ideal factors of the inverter.Combining the MRAS with the pulsating high frequency voltage injection method,the smooth switching between the two control algorithms is completed,and.the position sensorless control of the PMSM is realized at full speed range.Finally,the simulation model of position sensorless vector control of PMSM is established under Matlab/Simulink simulation platform,and the experimental verification is carried out on different types of PMSM experimental platform.Simulation and experimental results at different speeds show that this composite algorithm can estimate the rotor position of PMSM in full speed range.