Rotary Electric Machine Winding Segmentation for Dielectric Breakdown Prevention

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Solution Overview

Problem

Conventional three-phase rotary electric machine systems face complexity due to the need for insulators to prevent dielectric breakdown during high speed drive, which arises from voltage phase differences between used and unused windings, and this complexity is not adequately addressed by existing configurations.

Innovation Solution

A simplified configuration where windings for low speed and high speed drives are distributed across multiple slots per pole per phase, eliminating the need for insulators by ensuring windings for different drive states are not in the same slot, thus preventing voltage phase differences and simplifying the system structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If windings are disposed in one slot and insulators are provided between used and unused windings, then dielectric breakdown is prevented, but device complexity increases

Engineering Contradiction:
Improveprevention of dielectric breakdownVSAvoidconfiguration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the windings into separate groups (first windings for both speed ranges and second windings for low speed only) and distributes them across multiple slots per pole per phase. This segmentation eliminates the need for insulators between different winding groups within the same slot, as each slot contains only one type of winding, thereby reducing device complexity while maintaining reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-slot configuration to a multi-slot configuration, distributing windings across different spatial dimensions (multiple slots per pole per phase). This dimensional change allows the system to avoid the need for insulators within slots while still preventing dielectric breakdown through proper spatial separation of winding groups

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

2Force

If all windings are used during low speed drive, then large torque is generated, but voltage phase difference occurs during high speed drive

Engineering Contradiction:
ImprovetorqueVSAvoidvoltage phase difference
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The patent segments the windings into first windings (used in both speed ranges) and second windings (used only in low speed range), allowing selective activation of winding groups based on operating conditions. This enables large torque generation at low speed while preventing voltage phase differences at high speed by excluding the second windings from operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a dynamic winding switching mechanism where the connection state of different winding groups changes based on the operating speed range. During low speed drive, both first and second windings are connected in series for high torque; during high speed drive, only first windings are used, dynamically adapting the winding configuration to operating conditions

Inventive Principle:
Principle #15Dynamics

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 allows for efficient torque and speed management without dielectric breakdown issues, simplifying the system structure and preventing voltage-induced phase differences, thereby enhancing operational reliability and reducing complexity.

Implementation Method 1

a three-phase rotary electric machine system, the system comprising: a converter unit; an inverter unit; a motor including a stator and a rotor; and a winding switch unit, the converter unit being connected to the inverter unit via terminals, the inverter unit being connected to the motor, the motor being connected to the winding switch unit

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2624444B1Rotary electric machine system
Publication Date: 2021.08.25 YASKAWA DENKI KK
  • EP2624444B1 patent drawingFigure 1
  • EP2624444B1 patent drawingFigure 2
  • EP2624444B1 patent drawingFigure 3

AI summary

A rotary electric machine system includes a rotor; and a stator including windings for low speed drive to be used only during low speed drive, windings for low/high speed drive to be used during both low and high speed drive, and a plurality of slots provided per pole per phase. The windings for low speed drive and the windings for low/high speed drive are distributively wound on different slots in the slots per pole per phase.