Stator Winding Layout to Suppress Resonance in Rotating Machines

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Solution Overview

Problem

Existing rotating electric machines face issues with insulation performance due to resonance phenomena and voltage amplification, leading to potential short-circuiting and decreased space factor in windings, especially in wave and lap winding structures.

Innovation Solution

The rotating electric machine employs a stator winding configuration with series-connection coil groups, where unit coils are arranged in slots of the same phase within the same magnetic pole to enhance magnetic coupling, thereby suppressing resonance and improving insulation performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the insulating film is made thicker to improve insulation performance between phases, then insulation performance is improved, but interphase distance increases leading to decreased space factor and increased size

Engineering Contradiction:
Improveinsulation performanceVSAvoidinterphase distance
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent changes the winding configuration parameter from conventional wave/lap winding to a specific connection pattern where unit coils are connected in series within coil groups, and coil groups are connected in parallel. This parameter change in the electrical connection structure suppresses resonance and allows for reduced interphase distance while maintaining insulation performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful resonance phenomenon into a beneficial effect by strategically arranging unit coils in slots of the same phase within the same magnetic pole. This arrangement creates magnetic coupling that suppresses resonance currents, transforming the potential harmful resonance into a stabilizing effect that improves insulation performance

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Stability of the object's composition

If unit coils are connected in series in lap winding structure, then winding continuity is improved, but resonance currents in opposite directions may flow causing surge voltage and decreased insulation performance

Engineering Contradiction:
Improvewinding continuityVSAvoidinsulation performance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent segments the phase winding into multiple unit coils that are arranged in series within coil groups. Each unit coil is placed in specific slots, and the segmentation allows for controlled magnetic coupling between adjacent unit coils, suppressing resonance while maintaining overall winding continuity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces coil groups as intermediary structures between unit coils and phase terminals. These coil groups provide a structured connection pattern that mediates the electrical connection, ensuring continuity while enabling resonance suppression through specific slot arrangements

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively suppresses resonance and reduces voltage differences between unit coils, enhancing insulation performance and output efficiency.

Implementation Method 1

unit coils that are housed in slots of the same phase within the same magnetic pole... enhance magnetic coupling, thereby suppressing resonance

Methodology Applied
Scientific EffectMagnetic coupling: Electromagnetic Induction

Data Source

PatentEP3923453B1Rotating electric machine
Publication Date: 2025.09.03 DENSO CORP
  • EP3923453B1 patent drawingFigure 1
  • EP3923453B1 patent drawingFigure 2
  • EP3923453B1 patent drawingFigure 3A~3B

AI summary

A rotating electric machine includes a stator and a rotor. The stator includes a stator core that has a plurality of slots that are arranged in a circumferential direction and a stator winding that has a plurality of phase coils that are wound in the slots. The rotor is arranged so as to oppose the stator in a radial direction and has a plurality of magnetic poles in the circumferential direction. In the rotating electric machine, each of the phase coils has a plurality of series-connection coil groups that each includes n unit coils that are arranged to be wound in the circumferential direction. In each of the series-connection coil groups, a first end thereof is connected to a phase terminal for a respective phase and a second end is connected to a neutral point, and the series-connection coil groups are connected in parallel.