Research On Sensorless Control System Of Flux-intensifying Permanent Magnet Synchronous Motor

In order to deal with the global energy crisis and achieve sustainable economic and social development,it is necessary to speed up the process of replacing fuel vehicles with new energy vehicles.As the key of electric vehicle,the motor drive system plays a decisive role in the power and energy consumption of electric vehicles.With the advantages of high power factor,high torque output capacity and wide speed regulation,the permanent magnet synchronous motor(PMSM)has been widely used for electric vehicle applications.The traditional interior PMSM can generate reluctance torque by using the d-axis demagnetization current due to its salient pole characteristics,which improves its own torque output capability.However,the demagnetization current also brings demagnetization risks to the permanent magnet..In recent years,the fluxintensifying PMSM(FI-IPMSM)with reversed saliency has been received attentions.It can guarantee the torque output capacity,reduce the PM demagnetization risk,and widen the speed range.Noted that to achieve the high performance vector control for the drive control system of FI-PMSM,the accurate rotor position information obtained by mechanical sensors is needed.However,the mechanical sensors will increase the volume and cost of electric vehicles.Therefore,sensorless technology becomes the research hot.This thesis will study the sensorless control system of FI-PMSM.Also,the conventional control scheme of the control system will be optimized.Firstly,the research background and significance of the sensorless control system of FI-PMSM is described.Also,the structural characteristics,working principle of FIPMSM and electromagnetic performance are analyzed.Then,the mathematical model of FI-PMSM is established,and the control strategy of the motor is analyzed.Based on Matlab/Simulink simulation platform and d SPACE1003 experimental platform,the FIPMSM vector control system is simulated and experimentally analyzed.Secondly,the control system of traditional snesorless control algorithm of FIPMSM is studied.Two traditional high frequency injection algorithms are selected,and their principles are described and the control system is built.In the simulation platform,the advantages and disadvantages of the two control methods are compared.Subsequently,due to the secondary saliency of FI-PMSM,the estimated rotational speed and the estimated rotor position oscillation problem exists in sensorless control.Thus,a new sensorless control scheme for FI-PMSM drive control system is proposed.The influence of the secondary salient harmonics is analyzed in detail.Also,the adaptive filter is investigated to suppress the harmonics in sensorless control system.Then,experiments are carried out on the FI-PMSM sensorless control system based on the traditional method and the proposed method.It is verified that the method proposed in this paper can effectively suppress the observation oscillation that caused by the secondary saliency harmonics.Finally,a new magnetic pole discrimination method suitable for FI-PMSM is proposed.And it is verified based on the experimental platform.It verifies that the proposed discrimination method does not need to interrupt the high-frequency signal injection process,which can directly start without position sensor.