高速磁浮列车长定子直线同步电机铁耗分析

Iron loss analysis of long-stator linear synchronous motor in high-speed maglev train

常导高速磁浮列车采用长定子直线同步电机(LLSM)驱动,其定动子铁耗与运行速度紧密相关,准确计算铁耗并分析其影响因素对更高运行速度的磁浮列车非常重要,本文基于有限元分析了LLSM的铁耗。根据磁场特性为LLSM建立了三种仿真模型,分别计算没有被动子覆盖区域的定子铁心磁场和被动子覆盖区域端部、中间的定动子铁心磁场,采用快速傅里叶变换得到了磁通密度基波和高次谐波分量;基于通用铁耗分立计算模型计算了各次磁通密度分量产生的铁耗,再根据叠加原理把三个区域磁通密度分量产生的铁耗相加就可以计算得到一段1.2 km长定子下LLSM的铁耗;对比不同速度下的铁耗得到了运行速度对铁耗的影响规律,同时也分析了铁心材料对铁耗的影响。结果表明,长定子铁耗主要由磁通密度的基波和5次、7次谐波产生,而动子铁耗则主要由齿槽效应引起的6次谐波磁通密度产生,两部分铁耗都随着运行速度的提高而快速增大。

The long-stator linear synchronous motor(LLSM)is used to drive normal high speed maglev train.There are iron losses related to speed in the stator and mover,so it is very important to accurately calculate the iron loss and analyze its influencing factors for maglev train with higher operation speed.In this paper,the iron loss of the LLSM is analyzed based on finite element method.According to the feature of magnetic field,three simulation models are established,which can calculate the stator magnetic flux density in the area without mover,and the magnetic flux density of stator and mover in end area and middle area covered with mover.The fundamental and higher harmonic components of the magnetic flux density are obtained by fast Fourier transform.Based on the general discrete calculation model of iron loss,the iron loss generated by each component of the magnetic flux density is calculated,and then the iron losses of LLSM under a 1.2 km long stator can be calculated by summing all those components in three areas according to the superposition principle.Compared with the iron loss of different speeds,the influence law of operation speed on iron loss is deduced.In the same time,the influence of iron material on the iron loss is analyzed.The results show that the iron loss of the stator core is mainly generated by fundamental,5th and 7th harmonic components of magnetic flux density,while that of the mover core is produced by the 6th harmonic magnetic flux density,which is mainly caused by cogging effect.Both iron losses rapidly rise along with the increase of operation speed in maglev train.