Jet Engine Generator Electronic Commutator Frequency Control

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Solution Overview

Problem

Gas turbine engines in aircraft generate electricity with fluctuating voltage and frequency due to spool speed variations, requiring complex gearbox systems to maintain constant output, which increases weight, size, and maintenance costs.

Innovation Solution

A jet engine assembly with a synchronous electric generator and electronic commutator that controls the magnetic field rotation relative to the rotor, allowing for consistent electricity generation at a predetermined frequency, independent of spool speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a gearbox is used to mechanically couple the spool to the generator to maintain constant output speed, then the voltage and frequency stability is improved, but the device complexity, weight, and size increase

Engineering Contradiction:

Improvevoltage and frequency stabilityVSAvoidgearbox system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical gearbox system with an electronic control system. The electronic commutator uses electronic switching to control the magnetic field rotation speed independently from the rotor speed, eliminating the need for mechanical speed exchange devices while maintaining constant frequency output.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from mechanical speed ratio to electronic field rotation control. By controlling the electronic commutator to rotate the magnetic field at a predetermined speed regardless of rotor speed variations, the system maintains constant frequency output without mechanical intervention.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If a gearbox is used to maintain constant generator speed, then the electricity frequency stability is improved, but the system weight increases

Engineering Contradiction:

Improveelectricity frequency stabilityVSAvoidgearbox weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent substitutes the heavy mechanical gearbox with a lightweight electronic commutator system. The electronic components control the magnetic field rotation to maintain constant frequency, eliminating the need for heavy mechanical speed reduction or multiplication mechanisms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a gearbox is used to exchange speed between spool and generator, then the frequency output consistency is improved, but the maintenance requirements increase

Engineering Contradiction:

Improvefrequency output consistencyVSAvoidmaintenance complexity

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The patent replaces the mechanical gearbox with an electronic commutator, eliminating mechanical wear components such as gears, bearings, and lubrication systems. The electronic system has fewer moving parts and no mechanical contact wear, significantly reducing maintenance requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If the generator is directly driven by the variable speed spool, then the device complexity is reduced, but the voltage and frequency fluctuate

Engineering Contradiction:

Improvesystem complexityVSAvoidvoltage and frequency stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces an electronic commutator as an intermediary between the variable speed rotor and the output electrical system. This electronic mediator controls the magnetic field rotation to maintain constant frequency output while accepting variable speed input, without requiring a mechanical gearbox.

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 solution provides stable, constant-frequency electricity generation without the need for intermediary speed exchange devices, reducing system complexity, weight, and maintenance, while enhancing reliability and reducing costs.

Implementation Method 1

The generator further includes a synchronous electric machine comprising a rotor and a stator, with the rotor being operably coupled to the at least one spool... and an electronic commutator controlling the rotation of a magnetic field of the rotor relative to the rotation of the rotor such that the synchronous electric motor generates electricity

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3004565B1Jet engine assembly and method for generating electricity

Publication Date: 2021.05.19 GE AVIATION SYSTEMS LLC

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AI summary

A jet engine assembly includes a jet engine having at least one spool and a generator. The generator comprising a rotor and a stator, with the rotor being operably coupled to the at least one spool, and an electronic commutator controlling the rotation of a magnetic field of the rotor such that the electric motor generates electricity. Also, a method of generating electricity from a generator having a stator and a rotor, the method comprising controlling a rotation of a magnetic field to generate electricity.