| In order to deal with the problem of environmental pollution and energy consumption caused by traditional fuel vehicles,we need to vigorously develop new energy vehicles.It has become an irresistible trend of the times to promote the highquality development of the electric vehicle industry and accelerate the construction of an automobile power.As the key components of electric vehicles,its drive motor system determines the dynamic performance of electric vehicles.To meet the requirements of multiple operating conditions of electric vehicles,a five-phase fluxintensifying permanent magnet synchronous motor(FI-PMSM)is studied in this paper.With the design of flux enhancement,the motor can achieve the characteristics of inverse saliency,reduce the risk of demagnetization of permanent magnet,and improve the speed regulation range of the motor.Also,the characteristics of small torque ripple and strong fault tolerance can be achieved.Under the complex operating environment of electric vehicles,the position sensor in the motor drive system is prone to failure,which will result in the drive system to lose speed and reduce the system reliability.Therefore,based on the motor normal and fault conditions,the related research on the sensorless control of the five-phase FI-PMSM is carried out in this thesis.The main work is as follows:(1)The motor characteristics and drive control strategy of the five-phase FIPMSM are researched.The structure,electromagnetic characteristics,and inverse saliency characteristics of the five-phase FI-PMSM motor are analyzed,and its mathematical model is established.According to the characteristics of inverse saliency of the five-phase FI-PMSM,a new MTPA control strategy is proposed to make full use of its reluctance torque to exert the motor performance.With the related test experiments,the advantages of the operating efficiency and dynamic and steady-state performance of the proposed five-phase FI-PMSM drive system are verified.(2)Research on sensorless control of five-phase FI-PMSM under normal motor conditions was carried out.According to the high-frequency mathematical model of the five-phase FI-PMSM,the traditional sensorless control system based on pulsing highfrequency injection method is analyzed.Aiming at the problems of secondary saliency harmonics and dynamic performance in sensorless control,a method of suppressing secondary-saliency harmonics based on the adaptive band is proposed.The adaptive linear neuron filter(ADALINEF)is introduced to suppress the secondary-saliency harmonics.Also,the adaptive band filtering(ABF)is introduced to demodulate position signals to improve the dynamic performance of the drive system.Compared with the traditional sensorless control algorithm,it is verified that the proposed method can effectively reduce the error of rotor position observation and has better dynamic performance.(3)Research on fault tolerant position sensorless control under motor fault condition is carried out.Based on the fault model and traditional fault-tolerant control method,the influence of motor fault operation on the five-phase FI-PMSM sensorless control system is analyzed.Aiming at the problems such as the obvious large torque ripple and the deterioration of rotor position observation performance,a fault-tolerant sensorless control strategy based on disturbance adaptive controller(DAC)is proposed.Compared with the traditional method,the proposed strategy is verified with better dynamic and steady performance. |
