Hybrid Thrust Control Using Embedded Electric Machines

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Solution Overview

Problem

Existing turbofan and turboprop jet engines rely primarily on fuel-based control systems, which are slow to respond to thrust response errors, leading to excess fuel usage, sluggish speed response, increased engine wear, and poor speed holding.

Innovation Solution

An engine control system that allocates thrust control between a fuel controller and an electric machine controller, utilizing high-frequency electric machine dynamics to quickly correct thrust response errors, while the slower fuel dynamics maintain overall thrust, thereby improving thrust response and reducing fuel consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If fuel-based control systems are used to control thrust, then overall thrust can be maintained, but the response speed to thrust errors is slow

Engineering Contradiction:
Improvethrust response speedVSAvoidresponse time to thrust errors
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The thrust control system is segmented into two independent controllers: a fuel controller for overall thrust management and an electric machine controller for rapid corrections. This segmentation allows each controller to specialize in different time scales, with the electric machine handling high-frequency corrections and the fuel controller managing slower thrust variations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges the fuel-based thrust control system with an electric machine control system into a hybrid control architecture. The electric machine controller is integrated with the fuel controller to work together, combining the advantages of both systems: the reliability of fuel control and the rapid response capability of electric machines.

Inventive Principle:
Principle #5Merging (Combining)

2Loss of energy

If fuel-based control systems are used, then thrust can be controlled, but fuel consumption increases due to slower response

Engineering Contradiction:
Improvefuel consumptionVSAvoidthrust response speed
Core Design Contradiction:
Loss of energyVSSpeed

Solution Approach 1:

The system implements feedback control where the actual thrust is continuously monitored and compared with the desired thrust. The error signal is processed by both controllers, with the electric machine controller providing rapid corrections based on real-time feedback, thereby reducing fuel waste from slow response and excessive fuel usage.

Inventive Principle:
Principle #23Feedback

3Reliability

If fuel-based control systems are used, then thrust can be maintained, but engine wear increases

Engineering Contradiction:
Improveengine wearVSAvoidthrust response speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

By segmenting the control function, the electric machine controller handles high-frequency thrust corrections that would otherwise cause excessive fuel injection rates and engine wear. The fuel controller maintains overall thrust levels, reducing the mechanical stress and wear on the engine from rapid fuel-based corrections.

Inventive Principle:
Principle #1Segmentation

4Stability of the object's composition

If fuel-based control systems are used, then thrust can be controlled, but speed holding performance is poor

Engineering Contradiction:
Improvespeed holdingVSAvoidresponse time to speed changes
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The hybrid control system merges the stability of fuel-based thrust control with the rapid response capability of electric machines. The electric machine controller provides fast corrections to maintain speed, while the fuel controller ensures stable thrust delivery, achieving both rapid response and stable speed holding.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4336035B1High bandwidth control of turbofan/turboprop thrust response using embedded electric machines
Publication Date: 2026.02.11 GENERAL ELECTRIC CO
  • EP4336035B1 patent drawingFigure 1
  • EP4336035B1 patent drawingFigure 2
  • EP4336035B1 patent drawingFigure 3

AI summary

Systems and methods for high bandwidth control of thrust response for turbofan or turboprop engines are provided. Such systems and methods include an engine control system (100) that processes a rate command (104) and a feedback signal (112) from an engine to generate sperate fuel and electric machine control signals (202), (210) that respectively control fuel and electric machine dynamics (108), (106) of the engine to produce engine dynamics (110) that result in desired thrust response.