Aircraft Reserve Energy Control for Hybrid Battery-Generator Flight Paths

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Solution Overview

Problem

Battery-electric aircraft face challenges in meeting reserve energy requirements due to low energy density of rechargeable batteries, leading to increased weight and reduced range, and existing systems are inefficient for carrying reserve energy.

Innovation Solution

Implement a hybrid energy system with rechargeable batteries for primary energy and combustible fuel-based generators for reserve energy, optimizing power management and flight paths based on the operational state of the reserve energy system to minimize weight and emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reserve energy is carried in rechargeable batteries, then safety regulations are met, but aircraft weight increases significantly

Engineering Contradiction:
Improvereserve energy availabilityVSAvoidaircraft weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The energy system is segmented into two distinct parts: a primary energy system using rechargeable batteries for normal operations, and a separate reserve energy system using combustion engines and generators for emergency situations. This segmentation allows each subsystem to be optimized for its specific function, with the reserve system using higher energy density fuel storage rather than battery weight.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reserve energy function is extracted from the primary battery system and implemented as a separate combustion engine-based system. This extraction removes the need to carry excessive battery weight for reserve energy, as the reserve system uses a different energy storage medium (fuel) with higher energy density.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If reserve energy is carried in rechargeable batteries, then safety regulations are met, but maximum range is reduced

Engineering Contradiction:
Improvereserve energy availabilityVSAvoidmaximum range
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

By segmenting the energy system into primary (battery) and reserve (combustion) components, the aircraft can achieve extended range on battery power alone since the reserve fuel system adds minimal weight. The segmentation allows the primary battery system to be sized for optimal range without the penalty of carrying full reserve battery capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reserve energy function is extracted from the battery system and implemented separately using fuel-based combustion engines. This extraction enables the primary battery system to be optimized for range without the weight penalty of carrying sufficient battery capacity for both primary and reserve energy needs.

Inventive Principle:
Principle #2Taking out (Extraction)

3Weight of moving object

If reserve energy system uses combustion engines, then weight is reduced, but emissions increase

Engineering Contradiction:
Improveaircraft weightVSAvoidemissions
Core Design Contradiction:
Weight of moving objectVSObject-generated harmful factors

Solution Approach 1:

The combustion engine-based reserve energy system operates periodically only when required for reserve energy needs rather than continuously. This periodic operation minimizes emissions since the combustion engines run only during emergency situations or when additional range is needed, rather than being the primary power source.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The combustion engine system is extracted as a separate reserve energy source rather than the primary power system. This extraction limits emissions to only those periods when the reserve system is activated, rather than continuous emissions from a purely combustion-based aircraft.

Inventive Principle:
Principle #2Taking out (Extraction)

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 hybrid system reduces aircraft weight and emissions by efficiently utilizing both energy sources, allowing for reduced reserve energy carrying weight while maintaining performance and adhering to safety regulations.

Implementation Method 1

a reserve energy system comprising two or more combustion engines and two or more generators arranged to power the two or more electric motors

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

two or more combustion engines and two or more generators arranged to power the two or more electric motors

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4656522A1Reserve energy system and flight path control
Publication Date: 2025.12.03 COÖPERATIE ELYSIAN AIRCRAFT CO U A
  • EP4656522A1 patent drawingFigure 1
  • EP4656522A1 patent drawingFigure 2
  • EP4656522A1 patent drawingFigure 3

AI summary

A control system for an aircraft, the aircraft comprising: two or more propulsors; two or more electric motors, each electric motor configured to drive a corresponding propulsor; a primary energy system comprising a rechargeable battery arranged to power the two or more electric motors; and a reserve energy system comprising two or more combustion engines and two or more generators arranged to power the two or more electric motors. The control system comprises: a user interface configured to output an attitude required to execute a given flight path. Following initiation of operation of the reserve energy system, the control system is arranged to receive an indication of the operational state of the reserve energy system; and control the user interface to output: a first attitude corresponding to a first flight path when the detected operational state of the reserve energy system is a first operational state; and a second attitude corresponding to a second flight path when the detected operational state of the reserve energy system is a second operational state, wherein the second attitude is different from the first attitude. The first operational state is a state in which all engines and generators are operational, and the second operational state is a state in which one of the engines and/or one of the generators is not operational. Between the initiation of operation and the detection of the operational state of the reserve energy system, the control system is configured to output, to the user interface, a precautionary attitude which can be maintained when the electric motors are powered by the reserve energy system alone if the reserve energy system is in the second operational state.