中低速磁浮列车速度对悬浮力影响分析

Influence of Speed on Levitation Force of Medium−Low-Speed Maglev Train

电磁铁为中低速磁浮列车提供悬浮力,其与轨道发生相对运动时,在轨道上产生涡流,同时,轨道涡流产生的外加磁场抵消了部分电磁铁产生的原磁场,进而使得电磁铁提供的悬浮力下降.为此,首先分析轨道涡流的形成规律,以及列车不同速度时涡流对气隙磁场的影响,进一步研究了列车速度对悬浮力的影响;其次,采用叠片F轨的方法来抑制涡流效应,结合叠片F轨提升悬浮力的机理,分析F轨不同叠片层数结构下轨道涡流对悬浮力的影响;最后,以长沙磁浮快线电磁铁结构为例,使用有限元软件进行仿真分析.结果表明:使用叠片F轨后可以降低轨道中的涡流,随着叠片数量的增加,气隙磁场逐渐逼近静态条件下的气隙磁场;悬浮电磁铁模块的端部线圈以120 km/h的速度运动时,得到轨道为无叠片F轨时悬浮力为5.7 kN,轨道为两层叠片F轨时悬浮力为7.5 kN,相比较无叠片F轨悬浮力增长30%.

Electromagnet provides suspension force for medium−low-speed maglev train.When the electromagnet moves relatively to a rail,eddy current is generated on the rail.The external magnetic field generated by the track eddy current offsets part of the original magnetic field generated by the electromagnet,causing the decrease of the suspension force provided by the electromagnet.Firstly,the formation of rail eddy current and its effects on air gap magnetic field are analyzed at different vehicle speeds.The influence of train speeds on the suspension force is further studied.Secondly,the laminated F-rail is used to suppress eddy current effect.Combined with the mechanism of the laminated F-rail lifting suspension force,the influence of rail eddy current on the suspension force is analyzed with the F-rails of different laminated layers.Finally,the electromagnet structure of Changsha Maglev Fast Line is simulated by using finite element software.The results show that the laminated F-rail can reduce the rail eddy current,and the air gap magnetic field gradually approaches the one under static conditions.When the coil at the end of the electromagnet model moves at the speed of 120 km/h,the suspension force is 5.7 kN without the non-laminated F-rail and 7.5 kN with the laminated F-rail of two layers,increasing by 30%compared with the case of the non-laminated F-rail.