Hybrid Excited Claw-Pole Machines: Comparison between Different Topologies

The paper is devoted to a 3D finite element analysis (FEA)-based comparison between three claw-pole synchronous machines equipped with a dual excitation: dc and permanent magnet (PM) ones, yielding the so-called hybrid excitation. The topologies under comparison are: (i) the inter-pole PM hybrid excited claw-pole machine, (ii) the hybrid excited brushless claw-pole machine, and (iii) the PM-assisted hybrid excited brushless claw-pole machine. The study is initiated by a description of the different topologies and an analysis of their main flux paths. Then, a 3D-FEA is carried out with emphasis on the investigation of the torque production capability of the conventional claw-pole machine with a single dc excitation in the rotor. The 3D-FEA based investigation of the torque production capability is extended to the ones of the three hybrid excited topologies which are compared to the one of the conventional claw-pole machine, taken as a reference.