Research On Direct Torque Control Strategy For Finite Element Analysis Of 12/10 Class Permanent Magnet Flux Motor Switching Motor

As a new type of permanent magnet synchronous motor,flux switching permanent magnet(FSPM)motor has the magnets on the stator.At the same time,it has the advantages of simple rotor structure,high efficiency and good heat dissipation.Furthermore,the armature field is in parallel with the PM field and there is no risk of PM demagnetization.All the advantages before make it suitable for the aerospace engineering,electric vehicles and hybrid electric vehicles.This paper investigates a FSPM motor which stator/rotor type is 12/10 and explains the root cause of high sinusoidal flux-linkage by the principle of consistency and complementarity.In addition,a common finite element analysis software Ansoft/Maxwell is introduced and the whole process of modeling 12/10 pole permanent magnet flux switching motor by using the finite element simulation software Ansoft/Maxwell is analyzed in detail in this paper.Then,the working principle and electrical performance including no-load permanent magnetic field,three-phase permanent magnet flux,single-phase winding back EMF,three-phase inductance and three-phase mutual inductance and electromagnetic torque are analyzed by finite element simulation.The motor has high electrical torque and sinusoidal flux-linkage which makes it easy to control.However,due to its special stator-rotor structure,the permanent magnet flux switching motor has higher positioning torque and electromagnetic torque ripple than the common rotor permanent magnet synchronous motor.At the same time,the flux linkage equation,back EMF equation,inductance equation and torque equation of the permanent magnet flux switching motor are derived which provides a theoretical basis for different control algorithms for the electric drive system.On this basis,this paper focuses on the study of direct torque control(DTC)for single-phase open-circuit faults.By compensating for the missing flux and optimizing the space voltage vector table,the stator flux amplitude remains unchanged and the torque ripple is effectively reduced.Based on the research and analysis of the above electromagnetic characteristics and mathematical modeling,FSPM is suitable for BLAC occasions,the traditional vector control algorithm and direct torque control algorithm can be used in FSPM speed control system.In this paper,the direct torque control algorithm is introduced.The mathematical model of the control algorithm is derived theoretically,and the Matlab/Simulink simulation model of the system is established.The simulation results show that the direct torque control system of permanent magnet flux switching motor based on 12/10 pole structure has small transient adjustment time and high dynamic response performance.The writer works in a waterworks.For the better process control,we equip AC drives with direct control(DTC),and expect DTC's rapid torque response and accurate torque control to translate into more uniform product quality and higher process output.On this basis,this paper focuses on the direct torque control of the motor under single-phase open-circuit fault,and the influence of the lack of space voltage vector on the output torque of the motor in single-phase open circuit fault is analyzed.In order to suppress the torque ripple caused by the motor under asymmetric operation,this paper deduces the reconstruction of the space voltage vector under different single-phase open-circuit faults.By compensating the flux linkage missing from the fault phase and optimizing the switch vector table,the stator flux linkage amplitude remains unchanged,which effectively reduces the torque ripple and improves the steady-state performance of the motor under single-phase open-circuit faults.Finally,in order to verify the correctness of the theory,an experimental platform for direct torque control of 12/10 permanent magnet flux switching motor is built.On this basis,direct torque control is performed on the normal operation of the motor and the single-phase open circuit fault.The implementation results show that the fault-tolerant control strategy can achieve stable operation under single-phase open circuit fault,and the effectiveness and feasibility of the algorithm are verified.