Electrical Machine Phase Reconfiguration for Torque and Loss Control

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Solution Overview

Problem

Existing electrical machines face inefficiencies and reduced torque at high speeds due to increased electromagnetic losses and voltage supply limitations, which are not adequately addressed by current re-configuration methods like field weakening control.

Innovation Solution

The method involves dynamically switching between 3n- and 3(n+1) configurations of electrical phases in an electrical machine, allowing for reduced field weakening and maintaining a constant supply voltage, thereby minimizing harmonic losses and enhancing power and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If field weakening control is used to extend speed range, then operational speed is improved, but electromagnetic losses increase and efficiency decreases

Engineering Contradiction:
Improveoperational speedVSAvoidelectromagnetic losses
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the electrical machine re-configurable between different phase configurations (3-phase, 6-phase, 9-phase, 12-phase) based on operating speed. The control system dynamically switches between configurations to optimize performance at different speed ranges, transforming a static machine into an adaptive system that changes its electrical characteristics according to operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the electrical parameter of phase configuration to resolve the contradiction. By switching between 3n and 3(n+1) phase configurations, the machine alters its effective turns ratio and magnetic loading characteristics, enabling it to maintain optimal efficiency across a wide speed range without relying solely on field weakening control.

Inventive Principle:
Principle #35Parameter changes

2Speed

If field weakening control is used to extend speed range, then operational speed is improved, but maximum torque is reduced

Engineering Contradiction:
Improveoperational speedVSAvoidmaximum torque
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The dynamic re-configuration between different phase configurations allows the machine to maintain optimal magnetic loading at different speeds. By switching to appropriate configurations, the system preserves maximum torque capability even at extended speed ranges, overcoming the torque reduction inherent in traditional field weakening control.

Inventive Principle:
Principle #15Dynamics

3Reliability

If re-configuration between 3n and 3(n+1) phases is implemented, then field weakening is reduced and supply voltage is stabilized, but device complexity increases

Engineering Contradiction:
Improvesupply voltage stabilityVSAvoidre-configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the stator windings into multiple independent phase sets (3-phase, 6-phase, 9-phase, or 12-phase configurations) that can be independently controlled and switched. This segmentation allows flexible re-configuration while maintaining manageable complexity through modular control of each phase set.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrical machine is designed with universal stator windings that can serve multiple functions across different phase configurations. The same physical windings can operate in 3-phase, 6-phase, 9-phase, or 12-phase modes, eliminating the need for separate winding sets and reducing overall device complexity despite the re-configuration capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enables the electrical machine to operate with higher power and efficiency by adjusting the number of phases based on speed, reducing field weakening and supply voltage drops, while maintaining optimal torque and power delivery across varying speed ranges.

Implementation Method 1

A method of controlling an electrical machine (3) comprising stator windings (3a-3c) re-configurable between a 3-phase configuration and a 3n-phase configuration, where n is an integer in the range of 1 to N, is provided. The method comprises: applying a first set of voltages to the stator windings configured in the 3-phase configuration to generate a magnetic field to produce electromagnetic torque on a rotor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3618268B1Controlling of an electrical machine
Publication Date: 2024.07.24 ABB (SCHWEIZ) AG
  • EP3618268B1 patent drawingFigure 1~2b
  • EP3618268B1 patent drawingFigure 3a~4a
  • EP3618268B1 patent drawingFigure 4b~5a

AI summary

A method of controlling an electrical machine comprising stator windings which are re-configurable between a 3-phase configuration and a 3N-phase configuration, where n is an integer in the range of 1 to N, wherein the method comprises: a) switching the number of electrical phases of the electrical machine between 3-phase and 3n-phase based on an operating speed of the electrical machine, wherein switching between a 3n-phase configuration and a 3(n+1) configuration is performed in a speed range between n and (n+i) times a nominal speed of the 3-phase configuration.