Distributed Hybrid-Electric Propulsion for Aircraft Power Balance

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Solution Overview

Problem

Current mixed drive systems for aircraft, including combinations of reciprocating and jet engines, are not readily adaptable for commercial passenger aircraft, and hybrid-electric propulsion systems offer efficiency benefits but require innovative configurations for effective implementation.

Innovation Solution

Aircraft propulsion systems incorporating hybrid-electric powerplants (HEP) with parallel or in-line drive configurations, utilizing electric motors and heat engines, with optional battery support, are distributed across the aircraft to provide even or proportional propulsive power, and include fail-safe power transfer mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If hybrid-electric propulsion systems are implemented in commercial passenger aircraft, then fuel efficiency is improved, but system complexity increases

Engineering Contradiction:
Improvefuel efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The propulsion system is divided into multiple independent powerplants, each with its own heat engine and electric motor. This segmentation allows the complex hybrid-electric system to be broken down into manageable modules that can be independently controlled and maintained, reducing overall system complexity while maintaining fuel efficiency benefits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each powerplant is designed to perform multiple functions - it can operate in pure heat engine mode, pure electric motor mode, or hybrid mode. This multi-functionality allows the system to adapt to different operational requirements without needing separate systems for each mode, thereby reducing overall system complexity while improving fuel efficiency.

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

2Power

If multiple powerplants are distributed across the aircraft, then propulsive power distribution is improved, but device complexity increases

Engineering Contradiction:
Improvepropulsive power distributionVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The aircraft is equipped with multiple distributed powerplants rather than a single centralized engine. Each powerplant independently contributes to the total propulsive power, creating a distributed propulsion system that improves power distribution across the aircraft while managing complexity through modular architecture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple powerplants are combined to work together as an integrated propulsion system. The individual powerplants merge their output to provide distributed propulsive power, and they can also share common systems such as the battery energy storage system, which reduces overall device complexity despite having multiple power units.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If fail-safe power transfer mechanisms are implemented, then reliability is improved, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system incorporates fail-safe power transfer mechanisms that are prepared in advance to handle potential failures. If one powerplant fails, the system automatically transfers its load to other functioning powerplants before the failure impacts overall system operation, ensuring reliability while managing complexity through automated protection systems.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The propulsion system automatically detects and responds to powerplant failures without requiring external intervention. The fail-safe mechanisms self-activate to redistribute power and maintain operation, improving reliability while minimizing the complexity of manual systems or procedures.

Inventive Principle:
Principle #25Self-service

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

Enhances fuel efficiency and adaptability of hybrid-electric propulsion systems for commercial aircraft, ensuring reliable operation through balanced power distribution and redundancy in case of component failures.

Implementation Method 1

Each HEP includes an electric motor that transforms electrical energy to mechanical energy

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

Each HEP includes a heat engine that transforms thermal energy to mechanical energy

Methodology Applied
Scientific EffectThermal energy conversion: Heat Engine

Implementation Method 3

A battery is optional and may be used to provide electrical energy to the electric motor

Methodology Applied
Scientific EffectElectrochemical energy storage: Battery (electricity)

Data Source

PatentEP3931091B1Distributed propulsion configurations for aircraft having mixed drive systems
Publication Date: 2025.10.29 PRATT & WHITNEY CANADA CORP
  • EP3931091B1 patent drawingFigure 1~3
  • EP3931091B1 patent drawingFigure 4
  • EP3931091B1 patent drawingFigure 5~6

AI summary

An aircraft propulsion system is disclosed that includes at least one hybrid-electric powerplant for delivering power to an air mover for propelling the aircraft, wherein the at least one hybrid-electric powerplant includes a heat engine and an electric motor arranged in a parallel drive configuration or an in-line drive configuration.