This paper investigates a popular off-the shelf performance traction machine, a yokeless and segmented armature (YASA) axial flux surface permanent magnet machine, model P400HC from YASA Motors. A series of manual measurements and automated dynamometer tests were performed at various conditions. From these tests parameters are determined including friction and windage torque, phase resistance, permanent magnet flux linkage, and inductance. The efficiency, phase current, phase voltage, and power factor of the machine was measured over a wide torque, speed, and dc bus voltage range up to around the maximum ratings given by the manufacturer. A range of d-q current values were tested, showing that the machine is slightly salient since maximum torque is achieved when including a small amount of d-axis current. A Chevrolet Bolt electric vehicle (EV) was modeled with the YASA Motors machine and the stock Bolt EV machine. Over four different vehicle drive cycles, the YASA Motors machine was shown to be considerably more lossy than the Bolt EV machine, thereby achieving 4% to 5% less range. The higher loss of the YASA Motors machine likely has several causes, including higher phase resistance, significant friction, windage, and no-load iron losses, and the fact that Bolt EV machine was heavily optimized for an EV application while the YASA Motors machine was optimized to be a highly power dense more general-purpose machine.

This paper presents the mechanical design of a 70 kW Switched Reluctance Motor prototype with a nominal airgap length of 0.4 mm with a relatively large stator outer diameter of 280 mm. It presents the mechanical design considerations and manufacturing tolerances that are vital for an electric motor to maintain component integrity and meet performance requirements. Multi-stage design of the mechanical components and fittings for the complete mechanical system are presented and justified with finite element analysis results. The radial and axial stack-up analysis are presented which account for the dimensional variations during the manufacturing of motor components. The assembly of the motor prototype is described, which demonstrates that the axial and radial alignment of the motor components are achieved while maintaining the small airgap length required. The motor assembly is then verified with static end-of-line tests, such as winding insulation and housing leakage tests. Additionally, experimental modal analysis of the housing assembly is performed to examine the influence of the winding, housing, and potting on its modal frequencies and damping characteristics.

Refuse-collecting vehicles are significant polluters due to their expected drive cycles involving frequent stops and long idle periods. Electric refuse-collecting vehicles, still in their infancy, promise to address this through the replacement of internal combustion engines with batteries and electric traction motors. Today, typical motors for these vehicles involve heavy use of rare earth permanent magnets, which are subject to high price volatility, environmentally damaging mining practices, and occupational health hazards associated with refinement. The switched reluctance motor, which makes use of no permanent magnets, is a suitable substitute. This type of motor technology offers several advantages such as simple and robust construction, the ability to operate at high speeds and high temperature conditions, fault tolerance capability, and lower production costs in comparison with other technologies. This paper focuses on the design process of a switched reluctance motor for a battery electric refuse-collecting vehicle. The designed motor has a 36/24 outer rotor configuration, and its electrical and mechanical characteristics are based on the commercial traction motor TM4 SUMO HD HV3500-9P. The performance of the motor is evaluated using simulation tools such as JMAG and MATLAB/Simulink.

A generalized analytical solution for the 3-dimensional flux density field of an axial flux cylindrical Halbach Array is developed, based on existing work for 4-segment Halbach arrays. It is designed to reduce time, expense and knowledge associated with the traditional method of performing finite element analysis (FEA) to characterize such an array. It is applicable to the following applications: magnetic bearings, gears, couplings, generators and motors for electric vehicles. Halbach arrays of 4, 6 and 8-segment configurations are analyzed using the improved analytical method, then validated using FEA. The analytical equation is used to perform a sensitivity analysis on the 8-segment array.