Hybrid-Electric Aircraft Propulsion Charging by Turbomachine Operability

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Solution Overview

Problem

Hybrid-electric aircraft propulsion systems face challenges in safely charging electric energy storage units without damaging them or adversely affecting gas turbine engine performance, due to susceptibility of battery packs to damage and interference with engine operating conditions.

Innovation Solution

A method for operating a hybrid-electric propulsion system that involves determining the operability range of the turbomachine based on parameters like exhaust gas temperature, stall margin, and acceleration demand, and then charging the electric energy storage unit only when within a predetermined safe range, using an electric machine to generate and provide power while maintaining constant output power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If electrical power is provided to the battery pack to increase efficiency, then the hybrid-electric propulsion system efficiency is improved, but the battery pack may be damaged or fail due to improper charging

Engineering Contradiction:
Improvehybrid-electric propulsion system efficiencyVSAvoidbattery pack reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The control system continuously monitors battery pack parameters (temperature, charge state, voltage) and adjusts charging operations accordingly. When parameters indicate risk of damage or failure, the system automatically modifies or terminates charging to protect the battery pack, thus maintaining reliability while enabling efficient energy use during safe operating conditions

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes charging parameters (power level, charging rate, timing) based on real-time battery pack conditions and turbomachine operating state. This allows efficient charging when conditions are favorable while preventing damage when conditions deteriorate, resolving the contradiction between energy efficiency and reliability

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If the battery pack is charged during operation, then electrical power is stored for later use, but the charging process may adversely affect gas turbine engine performance

Engineering Contradiction:
Improveelectrical power stored in battery packVSAvoidgas turbine engine performance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The system dynamically determines charging eligibility by continuously monitoring turbomachine operability parameters (exhaust gas temperature, stall margin, acceleration demand). Charging operations are activated or deactivated in real-time based on whether the turbomachine is operating within a safe operability range, allowing electrical power storage when engine performance is not compromised

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system acts as an intermediary between the turbomachine and battery pack, mediating the charging process by evaluating engine conditions and selectively enabling or disabling charging. This intermediary function ensures that battery charging occurs only when it will not adversely affect gas turbine engine performance, thus preserving engine reliability while enabling energy storage

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If charging operations are restricted to maintain safety, then the risk of damage is minimized, but the efficiency of the hybrid-electric propulsion system is reduced

Engineering Contradiction:
Improvebattery pack and turbomachine safetyVSAvoidhybrid-electric propulsion system efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary assessments of charging conditions by monitoring turbomachine operability parameters before initiating charging. By evaluating exhaust gas temperature, stall margin, and acceleration demand in advance, the system determines whether charging is safe to proceed, thus maintaining safety while enabling efficient energy utilization when conditions permit

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control system integrates multiple functions: monitoring battery pack status, evaluating turbomachine operability, determining charging eligibility, and executing charging operations. This multi-functional approach allows the system to maintain safety through comprehensive monitoring while maximizing efficiency by enabling charging across various operating conditions when safe

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 minimizes the risk of damaging the energy storage unit and turbomachine, ensures efficient charging, and maintains optimal turbomachine performance by charging only when conditions are safe, thereby preventing premature wear or stall.

Implementation Method 1

an electric machine coupled to the turbomachine... operating the hybrid electric propulsion system in an electric generation mode to generate electric power with the electric machine

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4368824A1Propulsion system for an aircraft
Publication Date: 2024.05.15 GENERAL ELECTRIC CO
  • EP4368824A1 patent drawingFigure 1
  • EP4368824A1 patent drawingFigure 2
  • EP4368824A1 patent drawingFigure 3

AI summary

A hybrid-electric propulsion system 50 includes a turbomachine 102 and an electric machine 56 coupled to the turbomachine 102. A method for operating the hybrid-electric propulsion system 50 includes receiving information indicative of an operability parameter of the turbomachine 102; determining the turbomachine 102 is operating within a predetermined operability range based at least in part of the received information indicative of the operability parameter of the turbomachine 102; and operating the hybrid electric propulsion system 50 in an electric generation mode to generate electric power with the electric machine 56 in response to determining the turbomachine 102 is operating within the predetermined operability range.