On the sizing of the PM excitation of a hybrid claw pole alternator

The paper is devoted to a 3D-finite element analysis (FEA) of a hybrid-excited claw pole alternator (HECPA) with emphasis on the sizing of the permanent magnet (PM) excitation and it effect on the back-EMF production capability and eddy current loss. The HECPA is equipped by three sources of excitation : (i) a toroidal field in the stator, (ii) a NdFeB PM in the rotor and (iii) two lateral ferrite PMs mounted on the magnetic collector. The study is initiated by the description of the topology of the HECPA. Then, an analysis of the flux paths through the magnetic circuit is carried out, prior an investigating by 3D FEA of the effects on the PMs widths on the back-EMF production capability as well as on the eddy current loss. The study is achieved by the a 3D FEA-based computation of the features of the HECPA with optimized PM excitation.