Design and Performance Analysis of a Switched Reluctance Motor Using Finite Element Analysis and Magnetic Equivalent Circuit Model

By being magnet-free, and mechanically robust with a longer constant power range, switched reluctance motor (SRM) is gathering much attention as a potential choice to propel electric vehicles (EVs) and hybrid electric vehicles (HEVs). This paper comprehensively investigates the performance sensitivity to geometric design variables such as rotor diameter, pole arc angles, and yoke thicknesses for an SRM using static two-dimensional (2D) electromagnetic Finite-Element Analysis (FEA). The reason for the change in static characteristics due to variation in reluctance between SRM designs has not been detailed previously. This is addressed by the magnetic equivalent circuit (MEC) model that simplifies the design analysis. Results indicate that stator pole reluctance needs to be given due importance while studying the influence of rotor diameter. Also, it is imperative to set an adequate thickness of the stator and rotor yokes to minimize the effect of saturation on the performance. Rotor diameter and stator pole arc angle have a pronounced influence on the performance while the influence of rotor pole arc angle and yoke thicknesses was relatively less

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

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