Analysis of Stator/Rotor Pole Combinations in Variable Flux Reluctance Starter Generator with Flux gaps

This paper presents a comprehensive investigation of the influence of stator/rotor pole combination in a modular Variable Flux Reluctance Machine (VFRM) with a flux gap. The modular structure of the VFRM offers several advantages such as simplified manufacturing process, improved fault-tolerant capability, and potentially reduced material consumption. The VFRM utilizes independent direct current field (DC) excitation for flux regulation. First, the features of non-modular and modular VFRM are illustrated by using ideal air-gap permeance function. Next, the electromagnetic performance, including open circuit air-gap flux distributions, open circuit air-gap flux densities, flux linkage, back-EMF, self-inductance, mutual inductance of armature windings, and output characteristics are analyzed by comparing 12s8r, 12s10r, and 12s14r non-modular and modular VFRMs. The obtained output characteristics are validated through finite element analysis (FEA) results and prototypes.