Connected C-Core Hybrid SRMs for EV Applications

TL;DR

This paper introduces a new class of PM-assisted SRMs with innovative topologies and optimized PM placement, achieving higher torque density for EVs through analytical modeling, design optimization, and experimental validation.

Contribution

It presents a systematic investigation of eight motor topologies, introduces the point-of-conversion concept for PM placement, and validates a high-performance configuration for EV applications.

Findings

Torque density surpasses conventional SRMs.

Optimized PM placement reduces magnetic reluctance.

Experimental results confirm higher torque per PM volume.

Abstract

This paper proposes a new class of permanent magnet-assisted three-phase switched reluctance motors (PM-SRMs) designed to achieve significantly higher torque density for electric vehicle (EV) propulsion systems. Eight distinct motor topologies are systematically investigated, including a non-PM baseline design, three innovative PM arrangement strategies, and two optimized rotor/stator teeth configurations (22-pole and 26-pole variants). The study presents analytical models including magnetic equivalent circuits (MECs), detailed operating principles, and generalized design formulations that account for both electromagnetic and structural considerations. A key contribution is the introduction of the point-of-conversion (PoC) concept, which optimizes PM placement by minimizing magnetic path reluctance. Comparative analysis demonstrates torque density improvements over conventional SRMs and existing PM-assisted designs while maintaining structural robustness. Experimental validation confirms that the proposed 24/22 configuration with inter-phase PMs delivers higher torque per PM volume compared to state-of-the-art designs. The findings provide insights for EV motor designers seeking to balance performance, cost, and reliability.