Research On Permanent Magnet Linear Synchronous Motor With Double Side Dislocated High Speed Fractional Slot Concentrated Winding

Long primary double-sided permanent magnet linear synchronous motor(PMLSM)has the advantages of simple structure,high power factor,high efficiency,high thrust density,low normal force and thrust fluctuation,etc.and it is convenient to achieve segmentation when adopting fractional slot concentrated winding section.Therefore,this type of motor is very suitable for electromagnetic propulsion system.In this paper,the long primary double-sided fractional slot concentrated windings permanent magnet linear synchronous motor(FSCW-PMLSM)with is mainly studied in the following aspects:Firstly,according to the magnetomotive force characteristics of FSCW-PMLSM,the influence of the bilateral armature misalignment displacement on the magnetomotive force harmonics of each unit motor is analyzed.The eddy current loss of permanent magnet caused by the magnetic conductance harmonics under no-load condition and the eddy current loss of permanent magnet induced by armature harmonic magnetomotive force on loaded condition are deduced respectively.Secondly,through the finite element method,researches are conducted on the bilateral armature misalignment of FSCW-PMLSM with several typical slot-pole combinations windings.The effects of misalignment displacement on the eddy current loss of the permanent magnet,positioning force,thrust and thrust fluctuation under no-load and loaded condition are studied respectively,based on which,the optimal misalignment displacement is determined.By comparing the performances of the several slot-pole combinations,an optimal combination is determined.Thirdly,the finite element method is applied to optimize the motor structure parameters,the pole arc coefficient and the inclination angle of the magnetic poles.The different performances caused by different materials of the PM-fixed substrate are compared and analyzed.According to the optimization results and the selection of the fixed substrate material,an experimental prototype is manufactured and relevant experiments are carried out.Finally,the comparison of the copper loss and iron loss between the selected bilateral misalignment FSCW-PMLSM and its corresponding integer slot PMLSM are made.Through analyzing the difference between fractional slot and integral slot,the bilateral misalignment method of the integer slot motor is derived,thereafter,the influence of misalignment on the eddy current loss,positioning force,thrust and thrust fluctuation is studied.