Dual-Battery Propulsion Power Allocation for Peak Load and Weight

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Solution Overview

Problem

Current hybrid electric and fully electric systems face limitations due to the specific energy and specific power capabilities of batteries, leading to oversized and heavy batteries, which are not optimized for varying operational modes of aircraft or vehicles.

Innovation Solution

A system comprising a high-energy battery and a high-power battery, each designed for optimal performance in different propulsion modes, with a system controller that allocates load power dynamically based on operational demands and battery health, minimizing overall weight and avoiding oversizing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a single battery is sized to meet peak power demands, then power requirements are satisfied, but the battery becomes oversized and heavier than necessary

Engineering Contradiction:
Improvepeak power capabilityVSAvoidbattery weight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The battery system is segmented into two distinct batteries: a high-energy battery for energy-intensive operations and a high-power battery for peak power demands. This segmentation allows each battery to be optimized for its specific function rather than one battery having to handle all scenarios, thereby reducing overall weight while meeting both energy and power requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically allocates power between the two batteries based on real-time operational demands. The controller adjusts which battery supplies power and in what proportions, optimizing performance for each flight phase (climb, cruise, descent) and preventing either battery from being oversized for scenarios where it isn't needed.

Inventive Principle:
Principle #15Dynamics

2Weight of moving object

If high-specific-energy battery technology is used, then weight is reduced, but specific power capability is limited

Engineering Contradiction:
Improvebattery weightVSAvoidspecific power capability
Core Design Contradiction:
Weight of moving objectVSPower

Solution Approach 1:

The system separates the energy storage function (handled by the high-specific-energy battery) from the peak power delivery function (handled by the high-specific-power battery). This allows the high-energy battery to be optimized for weight and energy capacity without compromising peak power capability, as the high-power battery handles surge demands.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes operational parameters by switching between different battery configurations based on flight phase. During climb and descent, the high-energy battery provides sustained power. During takeoff and other high-power events, the high-power battery supplements or provides primary power, optimizing the balance between weight and power capability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If battery size is increased to meet all operational requirements, then reliability is improved, but device complexity and weight increase

Engineering Contradiction:
Improvesystem reliabilityVSAvoidbattery system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Rather than using one large, complex battery system that must handle all scenarios, the system segments functionality into two specialized batteries with a relatively simple control architecture. The controller monitors state of charge and power demands, then automatically manages power allocation, achieving high reliability through functional specialization rather than system complexity.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3960634B1System and method for allocating propulsion load power drawn from high-energy and high-power batteries
Publication Date: 2023.10.18 THE BOEING CO
  • EP3960634B1 patent drawingFigure 1
  • EP3960634B1 patent drawingFigure 2
  • EP3960634B1 patent drawingFigure 3

AI summary

System and method for allocating load power drawn from multiple batteries for powering propulsion of a vehicle. The system includes: high-energy and high-power batteries (18a; 18b) respectively designed for optimal production of DC power during high-specific-energy and high-specific-power propulsion; and battery health management systems (16a; 16b) configured to monitor state of charge and state of health of the batteries (18a; 18b) and generate battery status signals. The system further includes a propulsion load (26a; 26b) configured to produce propulsion force using power converted from power generated by at least one of the batteries (18a; 18b) and a system controller (12) configured to allocate load power drawn from the high-energy and high-power batteries (18a; 18b) for use by the propulsion load (26a; 26b) in dependence on a propulsion phase of the vehicle and the battery status.