Research On The Permanent Magnet Flux Monitoring Of PMSM

Permanent magnet synchronous motor(PMSM) has many advantages which are light weight, simple structure, low loss, high efficiency and so on, but for permanent magnet synchronous motor control system, at high temperatures or high current condition,the permanent magnet motor flux will be irreversible lossed, which causes the motor’s empty potential declining and may even cause damage to the motor, seriously affect the efficiency, performance and reliability of the motor, in order to reduce economic losses caused by the loss of flux failures, it must monitor the permanent magnet synchronous motor permanent magnets for loss of flux conditions,in order to minimize losses caused by the loss of flux which can reduce the maintenance costs. The main research is to monitor permanent magnet synchronous motor’s permanent magnet flux online based on EKF and its improved method.Firstly, analyze the status quo of the permanent magnet flux of permanent magnet synchronous motor’s monitor and the reason of flux loss; discuss the status of today’s motor control system; analyze the type and structure of permanent magnet synchronous motors, describe the principle of coordinate transformation, concentrate on deducing coordinate transformation of the permanent magnet synchronous motor and its mathematical model, introducing the vector control theory and SVPWM technology.Then, focus on discussing the Kalman filter and extended Kalman filter(EKF) working mechanism, improve the extended Kalman filter mathematical model, and reach the purpose which is the permanent magnet synchronous motors mathematical model combine ultimately flux permanent magnet motor for precise online monitoring.This thesis selects stator current and flux permanent magnet rotate coordinate system for the state variables, establish EKF(Extended Kalman Filter) and its improved systems to provide accurate permanent magnet flux information in real time and then build a simulation model of the system under matlab R2009 a dynamic simulation results to verify the feasibility of the proposed algorithm, testify that EKF filter system can accurately monitor the online information flux permanent magnet. Finally, the thesis gives the corresponding actual experiment platform designs.