Research On Sensorless Control Technology Of Fpmsm

Five-phase permanent magnet synchronous motor(PMSM)has the advantages of good fault tolerance,low torque ripple and high power density.It is widely used in electric ship propulsion,track traction,aerospace and other occasions with high reliability requirements.In some extreme environments,the use of position sensors will cause the reliability of the system to decline.The sensorless control can be used as the backup control scheme of the system.Therefore,this paper studies the five-phase PMSM full speed domain sensorless control technology.It includes the research of rotor position identification technology based on high frequency voltage injection method in low speed operation,the research of rotor position identification technology based on sliding mode observer(SMO)in medium and high speed operation,the research of rotor initial position detection method and the research of full speed operation control method.Firstly,the inductance matrix of five-phase PMSM is derived by using the winding function method,and then its mathematical model in natural coordinate system and rotation coordinate system is derived.Based on the mathematical model in the rotating coordinate system,the latest four vector pulse width modulation algorithm is studied,and a five phase PMSM vector control system is built on this basis.The effectiveness of the five phase PMSM vector control is verified by simulation using the control method id=0.Secondly,the pole position detection method based on high frequency rotating voltage injection is studied.Based on the five-phase PMSM mathematical model,the stator current mathematical model under high frequency voltage injection is derived.On this basis,band-pass filter and notch filter are used to demodulate the information related to rotor position in high frequency current,and phase locked loop(PLL)is used to observe the rotor position.Using Matlab toolbox to calculate the group delay of the filter and compensate the observation angle error;using the stator inductance matrix under the magnetic saturation to analyze the stator current model again,according to which,using the way of looking up the table to compensate the lag angle online;using the method of Taylor series expansion,the stator current model under the static magnetic saturation is analyzed in detail.According to this,the polarity of the magnetic pole is estimated by the second positive sequence component of the high frequency current,and the rotor position is estimated by the first negative sequence component,so as to estimate the position of the static magnetic pole quickly and accurately.Then,the pole position detection method based on SMO is studied.Based on the state equation of the fundamental subspace,the traditional SMO is established;in order to suppress the chattering phenomenon of the equivalent back EMF,the continuoussigmoid function is used instead of the sign function as the control law,and the improved SMO is established;the disturbance observer is established again with the current and back EMF as the state variables,so as to improve the angle observation accuracy of the system during the transient operation;the results of pole position observation and control system performance based on traditional SMO,improved SMO and disturbance observer are compared and analyzed.Finally,a five-phase PMSM driving control system experiment platform is built.This paper introduces the hardware structure and algorithm structure of the system,validates the five-phase PMSM static pole position detection principle by using the method of joint simulation,analyzes the state switching interval control algorithm,and validates the operation effect of the whole speed range by simulation,and verifies the effectiveness of the sensorless control method and the static pole position detection method based on the high frequency injection method by experiment.