Permanent Magnet Machine Technology in Traction Applications

Abstract:
The main motivating factor for using permanent magnet (PM) machines in traction applications is the increase in efficiency and higher torque and power density when compared to induction machines. The latter can lead to a reduced number of motors within a train or to lighter machines. Moreover, PM machines can be designed with high pole numbers, which means that direct drives without a gearbox can be constructed. The Siemens SYNTEGRA technology integrates a PM direct drive into a very compact and light bogie. This paper will give a short overview on the development of the PM technology in Siemens traction drives.