Aiming at the problem of thrust ripple in air-core permanent magnet linear synchronous motor(PMLSM)and the influence permanent magnet structure on the utilisation of permanent magnets,a trap-ezoidal Halbach consequent-pole of an air-core PMLSM with an optimised design was proposed for the Halbach array.Firstly,the electromagnetic performance of PMLSM in three pole configurations,Halbach array consequent-pole,double Halbach array and trapezoidal Halbach array consequent-pole,was com-pared by the finite element method.The air gap magnetic field harmonic components,back-EMF,thrust and thrust-to-volume ratio were calculated and compared respectively.Secondly,the equivalent magneti-zation intensity method was used to qualitatively analyze the effect of pole structure on the output perform-ance of the motor.The Kriging model was introduced and combined with a multi-objective optimization al-gorithm to optimize key parameters to improve the average thrust and thrust-to-volume ratio of the motor and reduce thrust ripple,and the Pareto front for the three optimization objectives was obtained.Finally,the results show that consequent-pole is more efficient and saves manufacturing costs.Trapezoidal Hal-bach array consequent-pole PMLSM effectively suppress thrust ripple and which remains at around 7%,and it is suitable for high-precision machining equipment.
关键词
永磁同步直线电机/Halbach阵列/交替极/等效磁化强度法/Kriging模型/多目标优化
Key words
permanent magnet linear synchronous motor/Halbach array/consequent-pole/equivalent mag-netizationintensity method/Kriging model/multi-objective optimization