Study On Sensorless Position Detection Technology Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor has been widely used for itsadvantages, such as compactness, high efficiency and reliability. Voctor controlof PMSM requires accurate position angle. In conventional control systems,optical encoders or electromagnetic resolvers are used for rotor position.However, these additional sensors increase the cost of system and decrease thereliability of system.The thesis takes embed PMSM as subject investigated, Based on thesensorless condition, Study on the rotor position detection of PMSM.Firstly, the state of the art review of PMSM sensorless control has beengiven based on many and international references. It describes the Researchstatus and progress of PMSM sensorless control method, development trend ofsensorless contol technology. This thesis presents the principles and realizationmethod of PMSM sensorless control based on high-frequency signal injection.Secondly, this thesis presents a method using high frequency voltal signalinjection, this method utilizes permanent magnet synchronous motor saliencyproperty, A high frequency voltage signal is injected in the motor stator winding,The salient pole motor modulated the current which was generated by the voltagesignal of high frequency, so the current of high frequency had the imformation ofrotor position, The filters are used to analyze high frequency current, This thesisimproves the filter, In this way, heterodyne method was used to extract theimformation relating to rotor position. The rotor position estimation methodwhich is based on Luenberger obserber is discussed in detail. A method usesmotor magnetic saturation model to accurately estimate the initial rotor positionand magnet polarity.Then, the simulation which is used by Matlab/Simulink for this method iscompleted. The results show this method is feasible.