Segmented Stator Winding for High-Speed Electric Motor Efficiency

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Solution Overview

Problem

Conventional stator winding methods for electric machines, particularly in electric vehicles, face limitations in increasing the number of rotations and reducing size while maintaining output efficiency, due to a small conductor-to-slot cross-sectional area ratio and difficulties in controlling the number of turns, which restricts high-speed operation and increases the size of the stator and rotor.

Innovation Solution

A stator winding configuration with segment conductors inserted into multiple slots, connected in parallel, and wound in series with a rectangular or circular cross-section, allowing for multiple layers and lead wires to connect phases, enabling efficient power distribution and reducing the cross-sectional area of each segment conductor to minimize alternating current resistance and enhance efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a wire having a relatively thin diameter is used for stator winding, then the winding can be formed around the slot, but the ratio of the occupied area of the conductor with respect to the cross-sectional area of the slot becomes relatively small, reducing operation efficiency

Engineering Contradiction:
Improvewinding formationVSAvoidoperation efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The stator winding is divided into multiple winding portions connected in parallel for each phase, with each winding portion having multiple segment conductors inserted into three or more slots for each pole. This segmentation allows each segment to have sufficient cross-sectional area while maintaining manufacturability through modular assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from using a single thick wire to using multiple thinner segment conductors arranged in parallel across multiple slots. This dimensional reorganization increases the effective conductor area ratio in the slot while maintaining ease of winding formation through standardized segment insertion.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of energy

If a rectangular copper wire having a relatively large width is used to form stator winding, then the cross-sectional area ratio of the conductor increases, but the size of the stator and rotor must be increased to enhance the output

Engineering Contradiction:
Improvecross-sectional area ratioVSAvoidstator size
Core Design Contradiction:
Loss of energyVSVolume of stationary object

Solution Approach 1:

By segmenting the winding into multiple portions with multiple conductors per slot, the patent achieves high effective conductor area ratio without requiring each individual conductor to be excessively large. The segmented structure allows efficient space utilization within the existing stator volume.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter configuration from single-conductor large-cross-section to multi-conductor distributed-cross-section. This parameter transformation maintains the effective conductor area ratio while allowing the stator and rotor sizes to remain compact, thereby enhancing output density.

Inventive Principle:
Principle #35Parameter changes

3Power

If a rectangular copper wire having a relatively large width is used for stator winding, then the output can be enhanced, but it is not easy to control the number of turns, resulting in a limit on high-speed operation

Engineering Contradiction:
ImproveoutputVSAvoidnumber of turns control
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The stator winding is segmented into multiple winding portions with multiple segment conductors each. This segmentation enables precise control of the number of turns through standardized modular units, facilitating high-speed operation while maintaining high output power.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By using multiple segment conductors inserted into multiple slots for each pole, the patent achieves excessive distribution of windings that provides both high output power and precise controllability of turn numbers through modular assembly, enabling operation above 7000 rpm.

Inventive Principle:
Principle #16Partial or excessive action

4Productivity

If the cross-sectional area of the conductor is increased to enhance output density, then the efficiency improves, but the size of the electromotor must be increased

Engineering Contradiction:
Improveoutput densityVSAvoidelectromotor size
Core Design Contradiction:
ProductivityVSVolume of stationary object

Solution Approach 1:

The patent segments the conductor system into multiple winding portions with multiple segment conductors distributed across multiple slots. This segmentation achieves high effective conductor area ratio for enhanced output density while maintaining compact electromotor dimensions through efficient spatial distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transforms the conductor configuration parameter from single large-cross-section to multiple distributed cross-sections. This parameter change enables high output density through increased effective conductor area ratio while keeping the electromotor size reduced, as the conductors are efficiently distributed within the existing volume.

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 configuration increases the number of rotations, enhances output density and efficiency, and allows for a reduction in the size of the electromotor while maintaining the same output, facilitating high-speed operation without significant torque ripple or vibration.

Implementation Method 1

a stator winding in which a winding having a rectangular shaped cross section or circular shaped cross section is wound in series around the slot

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an electromotor having the same, and an electric vehicle having the electromotor capable of increasing the number of rotations

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentEP2698901B1Stator of electric machine, electric motor provided with same, and electric vehicle provided with electric motor
Publication Date: 2019.08.28 LG ELECTRONICS INC
  • EP2698901B1 patent drawingFigure 1
  • EP2698901B1 patent drawingFigure 2
  • EP2698901B1 patent drawingFigure 3

AI summary

The present disclosure relates to a stator of an electric machine, an electromotor having the same, and an electric vehicle having the electromotor. A stator of an electric machine of the power saving interval may include a stator core having a plurality of slots, and a stator winding wound around the slot, wherein the stator winding has a plurality of winding portions connected in parallel with one another for each phase, and each of the winding portions has a segment conductor inserted into three or more slots for each pole. As a result, it may be possible to increase the number of rotations and reduce the external size thereof while maintaining the same output.