Research On Ac Loss And Temperature Rise For Permanent Magnet Motor With Series-parallel Combined Flat Wire Winding

Flattening the windings of electric-driven permanent magnet synchronous motor is an effective way to achieve low loss and high slot full rate of the motor windings,and is also one of the main technical routes to achieve lightweight and miniaturization of the motor.Aiming at the expansion and complement structure of flat wire winding and magnetic heat problems,this paper takes a 60 k W permanent magnet synchronous motor with flat wire winding as an example to research the distribution law of single and multistrand parallel flat wire winding,the connection mode of multistrand parallel flat wire winding and the temperature rise distribution of the motor with different flat wire winding forms.Firstly,the distribution law of single flat wire winding and multistrand parallel flat wire winding is analyzed,the two-dimensional and three-dimensional field-circuit coupling model of PMSM with different flat wire winding forms is established,the electrical density distribution of PMSM windings is calculated,and the size and variation law of winding DC loss,eddy current loss and circulation loss as well as the influencing factors are analyzed.It provides the basis for AC loss suppression.Secondly,in order to reduce the circulation loss of multistrand parallel flat wire winding,two series-parallel combination connection modes of cross series-parallel and misaligned series-parallel were proposed,and a two-dimensional finite element field coupling model of series-parallel combination flat winding permanent magnet synchronous motor was established.The circulation loss of cross Series-parallel flat wire winding and dislocation Series-parallel flat wire winding is calculated.The variation law of cross series-parallel winding circulation loss and misaligned series-parallel winding circulation loss were compared and analyzed,and the suppression effect of misaligned series-parallel connection on winding circulation loss was revealed,and the effectiveness of multistrand parallel flat wire winding series-parallel combination connection was verified.Finally,the three-dimensional finite element model of temperature rise calculation of PMSM with different flat wire windings is established,and the heat generation rate and heat transfer coefficient of each part of the motor with different flat wire windings are given,and the temperature distribution of each part of the motor under natural cooling is calculated.The distribution law of temperature rise of permanent magnet synchronous motor with single flat wire winding,cross series-parallel flat wire winding and misaligned series-parallel flat wire winding is revealed.