An Analytical Model for the AC Copper Losses in the Flat-Wire Motors

The flat-wire motors used in electric vehicles are characterized by high operating frequencies and large conductor cross-sections, making conductor AC losses during operation significant. Finite element analysis, commonly employed to address such losses, often demands substantial computational resources. To streamline the calculation process, this study proposes a novel formula for estimating the AC losses in flat-wire motor windings. The proposed formula accounts for the influence of stator slot leakage flux and enables loss estimation using only the RMS value of the steady-state stator current, electrical frequency, and the geometric parameters of the motor slots and conductors. Furthermore, the accuracy and practicality of the proposed method are validated through efficiency testing across the full operating range of the motor, and a comparison between the proposed method and another existing method has also been conducted.