Comparative assessment of a novel 8/18 multi-teeth with conventional 8/10 in-wheel SRM for an E-Scooter

Abstract

Electric scooters are increasingly gaining popularity in India owing to rising global crude oil prices and rising levels of vehicular pollution. Most of them are currently powered by expensive in-wheel (IW) permanent magnet (PM) brushless DC motors. Owing to their simplicity, and ruggedness while being cost-effective (since they do not employ PMs), switched reluctance motors (SRMs) are a viable alternative. Despite these benefits, SRMs possess drawbacks such as low torque density and inferior efficiency. Recently, a multi-teeth (MT) SRM with an improved performance was reported. However, the design of MTSRM topologies and their electromagnetic performance have not been explored sufficiently. In this paper, a design formula governing the selection of the number of MT and rotor poles for MTSRMs has been proposed. Using this, a novel four-phase 8/18 IW-MTSRM is derived and proposed for an E-scooter. The characteristics of the proposed SRM are numerically compared with a conventional 8/10 SRM based on magnetic characteristics, efficiencies and steady-state operation for the complete torque-speed range. Results indicate that the proposed 8/18 MTSRM has a higher peak torque capacity, torque density, superior drive cycle efficiency and reduced torque ripple. Further, the FEA model is validated experimentally on a downsized 8/18 MTSRM prototype.

KEYWORDS:

• Multi-teeth (MT) topology
• Electric scooter (E-scooter)
• performance comparison study
• In-wheel switched reluctance motor (IW-SRM)
• optimization
• prototype machine
• magnetic saturation

Acknowledgment

The research was performed in the Centre for System Design at the National Institute of Technology Karnataka, Surathkal, and is supported by the Ministry of Heavy Industries, Government of India under its project titled ‘Switched Reluctance Motor for 2W and 3W’ on the TPEM and FAME – India scheme [Grant no – F.No. 3(5)/2018-NAB-II(AUTO) (20331)].

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All necessary data and material can be made available.

Authors contribution

The authors contributed to the conception of the study, analysis and data interpretation, drafted the work and critically reviewed it. The authors’ agreed to be accountable for all aspects.

Consent to publication

The authors have obtained consent from the responsible authorities of National Institute of Technology Karnataka, Surathkal before the work has been submitted.

Additional information

Funding

This work was supported by Department of Heavy Industries, Govt of India: [Grant Number F.No. 3(5)/2018-NAB-II(AUTO) (20331)].