Research On The Electromagnetic,Vibration And Noise Of A Less Rare Earth Interior U Permanent Magnet Synchronous Machine

As the electric vehicle drive system, permanent magnet synchronous motor(PMSM) has obvious advantages. With the price of permanent magnet (PM) rising,the cost of PMSM increases significantly. Therefore, the necessity of less PMcontaining rare earth for designing PMSM is obvious. This paper is research onless rare-earth Interior U permanent magnet synchronous machine(LRE-IUPMSM).Firstly, with the high efficiency and wide speed range of LRE-IUPMSM, Twoslot coordination schemes are came up, one is36-solt-8-pole and the other is48-solt-8-pole. Besides, two kinds of winding are came up, too. One isconcentric-single-layer winding and the other is intersectional-single-layerwinding. With the fixed volume of PM, the shape and structure of PM areoptimized. A way of making symmetrical auxiliary-slot in rotor is put forward. Itreduces the loss of the stator effectively. And the main performance parameters ofLRE-IUPMSM are showed.Secondly, the noise of LRE-IUPMSM is researched because the worksituation of machine is complex. As the root causes of machine’s noise,electromagnetic force is analyzed necessarily and it is decided by air-gappermeance and magneto motive force. Combine with the situation of theLRE-IUPMSM, mathematical model of air-gap permeance, no-loadmagneto-motive force and load magneto motive force are put forward. The finiteelement model proves its validity.Thirdly, a3-D finite element model of LRE-IUPMSM is constructed. And theinherent modal frequencies of machine are analyzed. The influence of the statoryoke, the stator tooth, chassis, winding, end winding on the natural modalfrequencies is put forward. A3-D finite element model with end winding andchassis is the last model of LRE-IUPMSM inherent modal.Finally, Based on the principle of motor vibration, the different number ofradial electromagnetic force is attached on the stator tooth of3-D finite elementmodel. The noise of LRE-IUPMSM in different situation is given. A solution ofcasting resin is put forward. It improves the motor intrinsic modal frequencies andmakes noise and vibration deformation smaller. In the last, a3-D finite elementmodel proves it.