An Enhanced Axial-Flux Magnetic-Geared Machine with Dual-Winding Design for Electric Vehicle Applications

Abstract

Axial-flux magnetic-geared machine (MGM) is a promising solution for electric vehicle applications for combining the virtues of both axial-flux electric machine and magnetic gear. However, generalized MGMs are limited by the torque density issue, accordingly inapplicable to industrial applications. To solve the abovementioned issue, an improved axial-flux magnetic-geared machine with a dual-winding design is proposed. The key merit of the proposed design is to achieve enhanced torque performance and space utilization with the proposed design, which installs a set of auxiliary winding between modulation rings. With the proposed design, overload protection capability, and fault-tolerant capability can be also achieved, for the proposed machine can work with either the excitation of armature windings or auxiliary windings. The pole-pair, slot combination, and parametric design is studied and optimized by the 3d finite-element method and designed C++ optimization software. Electromagnetic analysis and performance comparison indicate that the proposed machine can achieve a torque enhancement of 68.6% compared to the comparison machine.

A Novel, Simple, and Flexible Fault-Tolerant Control Algorithm for Multiphase Electrical Machine Operation Under Open Circuit Faults

“…Therefore, an optimal compromise between safety and complexity is one important issue faced worldwide by many researchers in the recent literature, leading to the need of providing accurate algorithms capable of detecting fault conditions, allowing the machine to operate even in critical conditions during short-circuits or open-circuit of some of the phases supplied by the electrical drive. In this scenario, since when the first prototypes of multiphase machines were realized in the late '60s [5], several control strategies have been developed to detect and face fault conditions occurring in one or more phases of the machine, allowing the continuity of operation of the related drive system [6][7][8][9][10][11][12]. More in detail, two main categories of control strategies can be identified, covering the possible faults of different nature, such as Open Circuit Faults (OCF), Short Circuit Faults (CSF) between the interturns of the winding or at its terminals, and so on.…”