Flux Switching Machine With Permanent Magnet Generator

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Solution Overview

Problem

Conventional electrical machines, such as aircraft generators, are limited by the reliability of rotating diodes in brushless exciter drives, which can lead to system robustness issues due to their susceptibility to failure.

Innovation Solution

A two-stage flux switching power generation system incorporating a flux switching machine (FSM) with a steel rotor and a permanent magnet machine (PMM), where the PMM is connected to the FSM through a controller that includes a rectifier and power converter, allowing for self-sustaining operation without a rotating exciter or rectifier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a brushless exciter drive with rotating diodes is used, then the generator can provide self-sustaining operation, but the system reliability deteriorates due to rotating diode failure susceptibility

Engineering Contradiction:
Improveself-sustaining operationVSAvoidsystem robustness
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent removes the rotating diodes and brushless exciter components from the system. Instead of using a traditional brushless exciter drive, the invention employs a flux switching machine with stationary magnets and a controlled rectifier system, thereby extracting out the unreliable rotating components while maintaining self-sustaining operation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical brushless exciter system with rotating diodes with an electrical flux switching system using stationary permanent magnets and electronic control. This substitution eliminates the mechanical wear and reliability issues associated with rotating diodes while achieving the same self-sustaining function through electronic commutation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Extent of automation

If a brushless exciter drive with rotating diodes is used, then the generator can provide self-sustaining operation, but the device complexity increases due to additional components

Engineering Contradiction:
Improveself-sustaining operationVSAvoidsystem complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The patent extracts and removes the complex brushless exciter drive system with rotating diodes, replacing it with a simpler flux switching machine configuration using stationary permanent magnets and a controlled rectifier, thereby reducing overall system complexity while maintaining self-sustaining capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of placing magnets on the rotor and windings on the stator (conventional approach), the patent inverts the configuration by placing permanent magnets on the stationary stator and using a steel rotor with controlled flux switching. This inversion simplifies the system by eliminating rotating electrical contacts and complex exciter mechanisms.

Inventive Principle:
Principle #13The other way round (Inversion)

3Extent of automation

If a brushless exciter drive with rotating diodes is used, then the generator can provide self-sustaining operation, but the weight increases due to additional components

Engineering Contradiction:
Improveself-sustaining operationVSAvoidsystem weight
Core Design Contradiction:
Extent of automationVSWeight of moving object

Solution Approach 1:

The patent extracts and eliminates the heavy rotating diodes and brushless exciter components from the system. By using stationary permanent magnets on the stator and a simplified flux switching mechanism, the invention reduces the overall system weight while maintaining self-sustaining operation capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent inverts the conventional arrangement by placing permanent magnets on the stationary stator rather than on the rotating rotor. This inversion eliminates the need for heavy rotating electrical components and reduces the weight of moving parts while achieving self-sustaining operation through flux switching control.

Inventive Principle:
Principle #13The other way round (Inversion)

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

The system provides enhanced reliability and fault safety by eliminating the need for a rotating exciter and rectifier, ensuring continuous operation and efficient energy conversion while reducing weight and complexity.

Implementation Method 1

a permanent magnet machine (PMM) including a PMM rotor operatively connected to a PMM stator, the PMM rotor operatively connected to a second shaft, wherein the PMM is electrically connected to the FSM

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The controller can include a rectifier for rectifying energy between the PMM and the FSM

Methodology Applied
Scientific EffectRectification: Diode

Implementation Method 3

the FSM includes both an electromagnet for creating a magnetic field and multi phase winding to produce power

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Data Source

PatentEP3021478B1A two stage flux switching machine for an electrical power generation system
Publication Date: 2020.01.08 HAMILTON SUNDSTRAND CORP
  • EP3021478B1 patent drawingFigure 1
  • EP3021478B1 patent drawingFigure 2

AI summary

An electrical power generation system includes a flux switching machine (FSM) 101 including an FSM rotor 101a operatively connected to an FSM stator 101b, the FSM rotor operatively connected to a shaft 105, wherein the FSM includes an electrical input/output (i/o) 101c in electrical communication with the FSM stator, and a permanent magnet machine (PMM) 103 including a PMM rotor 103a operatively connected to a PMM stator 103b, the PMM rotor operatively connected to a shaft, wherein the PMM is electrically connected to the FSM.