Variable Cross-Section Motor Conductors for Lower AC Losses

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electric motors, particularly those with axial and radial flux configurations, suffer from significant alternating current (AC) losses due to heterogeneous current density distributions and variable magnetic fields, which current systems fail to adequately address.

Innovation Solution

The implementation of variable conductor widths and axial or radial rotor skew in electric motors, combined with dual stators and rotors, to balance AC and direct current (DC) losses by strategically positioning conductor elements with varying widths and cross-sections to optimize magnetic flux paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional conductors with uniform cross-section are used, then manufacturing is simple, but AC losses are high due to heterogeneous current density distribution

Engineering Contradiction:

ImproveAC lossesVSAvoidconductor geometry complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The conductor elements are designed with non-uniform cross-sections where different portions have different widths. Specifically, conductor elements have a first width at a first end and a second width at a second end, with the widths being different. This local variation in geometry optimizes current density distribution in different regions of the conductor, reducing AC losses by addressing the heterogeneous current distribution problem locally rather than requiring uniform design throughout.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs asymmetric conductor element designs where the cross-sectional dimensions vary along the length of the conductor. The conductor elements feature asymmetric width variations with respect to their longitudinal axis, creating intentional geometric asymmetry that counteracts the asymmetric current density distribution caused by skin effect and proximity effect, thereby reducing AC losses.

Inventive Principle:

Principle #4Asymmetry

2Stability of the object's composition

If conductor elements with varied widths are used, then current distribution becomes more homogeneous, but manufacturing precision requirements increase

Engineering Contradiction:

Improvecurrent density homogeneityVSAvoidconductor width variation precision

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent implements controlled parameter changes in the conductor geometry by varying the width of conductor elements along their length. The width transitions from a first width at one end to a second width at the other end, with specific width ratios and transition profiles that optimize current distribution. These parameter changes are designed to compensate for the non-uniform current density caused by electromagnetic effects, achieving more homogeneous current distribution while maintaining manufacturability through defined geometric progressions.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively reduces AC losses, enhances motor efficiency, increases slot-filling factor, and optimizes conductor geometry for homogeneous current distribution, thereby improving overall motor performance.

Implementation Method 1

A first source defines a magnetic field produced by a skin effect of the conductor itself

Methodology Applied

Scientific EffectSkin effect: Skin Effect

Implementation Method 2

A second source defines a magnetic field produced by other magnetic sources including proximity effects

Methodology Applied

Scientific EffectProximity effect:

Data Source

PatentUS12603559B2Variable cross-section conductors to reduce alternating current losses for axial flux, radial flux and motors with skew

Publication Date: 2026.04.14 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A vehicle electric motor system includes an electric motor having a rotor. Multiple windings are mounted on the rotors individually having a coiled conductor including multiple conductor elements. A width of successive ones of the conductor elements is varied. At least one of the multiple conductor elements includes a continuous tapering body on the axis and alternatively at least one of the multiple conductor elements includes a smallest cross-sectional area having a first thickness approximately at a midpoint of the at least one of the multiple conductor elements and opposed ends positioned oppositely about the smallest cross-sectional area individually having a conductor element second thickness greater than the first thickness.