Design And Research On A Novel Transverse Flux Machine Based On Scalar Potential 3D FEM

Transverse flux permanent magnet machine(TFM or TFPM) has the advantages of high output force density, large starting torque and good low speed performance as well as design flexibility. So TFM has attracted more attention. But because of its complex structure and magnetic field, high manufacture cost, and low power factor, the TFM's application is limited so far. This dissertation focuses on the design and research on a novel TFM with E-shaped stator core.A novel structured TFM is developed in this dissertation with E-shaped stator core. Its inner arm, outer arm and yoke are in the same plane so that they can be stacked by laminated silicon steel directly, which can greatly reduce the manufacture difficulty and cost. According to this structure, a special ring is designed to fasten the bridge core, which can keep the bridge core in position accurately and make it have good mechanical intensity. There is an electric angle difference of (2kπ + π/N) between each phase so that there does not exist dead point any longer in starting procedure and the cogging torque and torque ripple can also be reduced. The E-TFM equivalent magnetic circuit is established and the calculating formula of the main dimensions is also deduced.Because of the complexity of the TFM field, it is not accurate enough to use 2D method to analyze it and then a 3D method is necessary. The key points are the calculation time and accuracy for 3D analysis. The scalar potential is adopted in this thesis, which has much fewer variants than the vector potential. So the calculating time can be greatly reduced. The general method to process the current area and magnet is deduced as well as the method to process some special current areas in different coordinate systems. A 3D FEM application software is programmed to analyze the E-TFM field based on scalar potential. Some technics such as non-zero elements storage method, ICCG method and Newton-Raphson method are used during calculating, which can improve the calculating speed and accuracy.With the help of the programmed software, the magnetic field of an E-TFM prototype is analyzed and some parameters are calculated. The acquired results are the...