Research On Loss And Heat Dissipation Of Fractional-slot Concentrated-windings Permanent Magnet Motor With ISG

ISG(Integrated Starter Generator)is the key technology,and also one of the most popular research topics of hybrid Electric Vehicle.Permanent Magnet Synchronous Motors with Fractional-Slot Concentrated Winding have advantages such as high power density,high efficiency,small quality,high flux-weakening capability,flat structure,etc.These advantages allow this kind of motors to be ISG ones.This article aims to solve the problem of ISG motors’ differential heat dissipation in terrible working conditions.Finite Element Analysis is used to analyze the loss and heat dissipation situations of Permanent Magnet Synchronous Motors with Fractional-Slot Concentrated Winding.The influence on the eddy current loss of Permanent Magnet with different slots and poles was analyzed in this paper.According to the calculation results,large permanent magnet harmonic can be generated under the combination of same number of slots with different poles(e.g.8 poles with 9 slots,and 10 poles with 9 slots).A more powerful reverse rotating magnetic field is formed in the magneto motive force than the fundamental wave.The influence of the stator slot shoulder height on the loss of motor is analyzed and the generation conditions are discussed.Based on the results of simulation,the design principles of the slot shoulder angle and slot shoulder height are presented.As shown in the research results,the slot shoulder height can make a big difference in motor function improvement when the slot shoulder angler is small,and the slot shoulder height is 2 times smaller than the length of the air gap.In this paper,a better-improved design of the cooling structure of the motor is given and a comparison of the flow rate,and the temperature of the fluid and the cabinet has been made of these two cooling structures.It shows in the simulation results that there are surely improvements towards local high temperature and the heat dissipation ability.Besides,a sample motor is manufactured for the research and the results of the back EMF experiment and the load experiment are mostly in accordance with those of the simulation.Thus,the research method and the principle of design presented in this paper are proved to serve as a meaningful guide to industrial motor design.