The Study Of Rotor Position Estimation Algorithm For Dual-Winding Fault-tolerant Permanent Magnet Motor

As a core part of electric drive system,the sustainability and reliability of motor and its control system is very important.The dual-winding fault-tolerant permanent magnet motor(FTPMM)has not only high power factor,good dynamic and static performance,but also has the capability of fault tolerance.In the event of a fault,the motor is able to keep running through the corresponding control strategy.When controlling a dual-winding FTPMM,the speed and rotor position information are often required.In order to obtain speed and rotor position information,mechanical sensors are usually selected,such as encoder and rotating transformer.These mechanical sensors are not only bound to increase the complexity of the system,but also affect the system reliability as well as dynamic and static performance of the system.Therefore,it is very necessary to study the rotor position estimation algorithm of dual-winding FTPMM.In this thesis,the rotor position estimation method based on the back-EMF method is studied.Firstly,the structural characteristics,mathematical model,hysteresis control method of the dual-winding FTPMM and the fault-tolerant control strategies under different fault conditions of it are introduced.Secondly,in view of the dual-winding FTPMM,the back-EMF method is put forward that is suitable for fault-tolerant control to estimate the position of the rotor.In allusion to the problem that the method is easily affected by the motor parameters,the on-line parameter identification method is studied.Then,the simulation model of the sensorless control system of dual-winding FTPMM is built by Matlab/simulink based on the back-EMF method.The sensorless control system of the motor was simulated in the condition of no fault,single-phase fault and two-phase fault respectively.The simulation results show that the back-EMF method is able to estimate the rotor position accurately both in normal operation and in open circuit fault condition.Finally,hardware design and software design of the sensorless control system of dual-winding FTPMM are carried out.On the experimental platform,the rotor position estimation algorithm of the dual-winding FTPMM is tested to prove the correctness of the rotor position estimation algorithm.