No-Load Characteristic Computation for Wound Field Synchronous Propulsion Motors

This paper presents a fully analytical procedure for the computation of the no-load characteristic of salient-pole wound field synchronous machines. The proposed method consists of applying the Ampere's law to the magnetic circuit along the d-axis divided into five different parts. The procedure considers the magnetic shunt of the stator slots and the distortion of the air gap flux density caused by the lamination saturation. Moreover, the waveform of the air gap flux density also takes into account the anisotropic shape of the rotor pole. The procedure has been validated by means of finite elements simulations on two different machines.