Lumped Circuit Accounting for the Rotor Motion Dedicated to the Investigation of the Time-Varying Features of Claw Pole Topologies

This paper is aimed at the derivation and the resolution of a new lumped circuit-also called magnetic equivalent circuit (MEC)-based model of claw pole alternators (CPAs). Incorporating the rotor motion, the proposed MEC is intended to the investigation of the time-varying features of CPAs. Furthermore, it considers the saturation and the armature magnetic reaction. For the sake of simplicity, the MEC is derived assuming that the stator teeth and yoke are independent of the rotor position. Moreover, a specific hypothesis considering that the claws have the same shape along the axial direction with an opening equal to the one of the median plane is adopted. A dedicated numerical procedure based on the Newton-Raphson algorithm is developed in order to solve the proposed MEC. Hence, the prediction of selected time-varying features, considering both no-load and load operations, turns to be feasible. The comparison between the MEC results and those yielded by experiments carried out on a test bench, has led to good agreement.