Traction motor

Power density

Torque ripple

Traction (geology)

Powertrain

Induction motor

Engineering

Power (physics)

Driving cycle

Multiphysics

Direct torque control

Physics

Finite element method

Torque

Torque density

Structural engineering

Electric vehicle

Quantum mechanics

Magnet

Voltage

Computer science

Electrical engineering

Automotive engineering

Mechanical engineering

Thermodynamics

IEEE Transactions on Industry Applications

Performance trade offs for achieving high torque density and high drive-cycle efficiency in spoke-type permanent magnet (PM) motors are investigated. Unlike the traditional method, which relies on analytical equations, this trade-off study is conducted through a statistical analysis of the Pareto-optimal design candidates resulting from a large-scale design optimization of an example traction machine over a Le Mans-based drive cycle. In the design optimization process, both low-speed and extended-speed/field-weakening operating regions are evaluated using high-fidelity electromagnetic finite element (FE) simulations with an objective to simultaneously increase the torque density and decrease the power losses over the high energy-throughput-zones of the machine torque-speed plane. The resultant 3400 design candidates are utilized to investigate the impact of increasing power density on other important performance metrics such as power losses, PM demagnetization, and torque ripple. This analysis is supplemented by multiphysics simulation of three counterpart optimized designs and successful experimental verification of a prototype of one of those three designs which represents a record high power density motor in traction applications.

Design Optimization of a High Torque Density Spoke-Type PM Motor for a Formula E Race Drive Cycle