Distributed Propulsion Power Unit Control via Selective Coupling

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Solution Overview

Problem

Distributed propulsion systems face challenges in efficiently managing power units to achieve desired propulsive forces while minimizing fuel consumption and maintaining system balance, particularly in aircraft where large engines can lead to unbalanced propulsive forces and increased drag.

Innovation Solution

A distributed propulsion system with a controller that selectively couples and decouples power units to propulsors based on desired throttle values, determining the necessary number of power units to achieve the desired propulsive force, allowing for efficient operation by enabling or disabling power units as needed, thereby optimizing thrust specific fuel consumption and reducing the need for large control surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If large engines are used to achieve desired propulsive force, then the propulsive force requirement is met, but the system becomes unbalanced and drag increases

Engineering Contradiction:
Improvepropulsive forceVSAvoiddrag
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The propulsion system is divided into multiple smaller power units distributed across the vehicle rather than using one or two large engines. This segmentation allows for better weight distribution, reduced drag, and improved aerodynamic efficiency while maintaining the required total propulsive force.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system allows for asymmetric operation where individual power units can be independently controlled and coupled to propulsors based on specific flight conditions, enabling optimized thrust distribution that reduces overall drag while meeting propulsive force requirements.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If multiple power units are continuously operated to maintain system readiness, then reliability is improved, but fuel consumption increases

Engineering Contradiction:
Improvesystem readinessVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically couples and decouples power units to propulsors based on real-time thrust requirements. The controller monitors desired thrust levels and selectively engages only the necessary number of power units, transitioning the system from static continuous operation to dynamic on-demand operation, thereby reducing fuel consumption while maintaining reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The operational parameters of the power units are changed by adjusting the number of actively coupled units based on thrust demand. The system modifies its configuration by coupling additional power units when thrust requirements increase and decoupling them when requirements decrease, optimizing the balance between reliability and fuel consumption.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If power units are selectively coupled and decoupled to optimize fuel consumption, then thrust specific fuel consumption is improved, but system complexity increases

Engineering Contradiction:
Improvethrust specific fuel consumptionVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The controller implements a feedback mechanism that continuously monitors the desired thrust level and compares it with the current thrust output. Based on this feedback, the controller automatically determines which power units should be coupled or decoupled, managing the complexity through automated closed-loop control rather than requiring complex manual coordination.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system manages the selective coupling and decoupling of power units autonomously based on pre-established coupling sequences and thrust requirements. The system serves itself by automatically making coupling decisions without requiring external intervention, thereby managing the increased complexity through self-contained automated control logic.

Inventive Principle:
Principle #25Self-service

4Power

If all power units are coupled to all propulsors for maximum thrust capability, then propulsive force capability is maximized, but system efficiency decreases

Engineering Contradiction:
Improvethrust capabilityVSAvoidsystem efficiency
Core Design Contradiction:
PowerVSProductivity

Solution Approach 1:

The system applies partial action by coupling only the necessary number of power units to propulsors based on current thrust requirements rather than keeping all power units coupled at all times. This partial engagement maintains maximum thrust capability when needed while improving efficiency during normal operation by avoiding unnecessary power unit operation.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3372506B1Distributed propulsion system power unit control
Publication Date: 2019.10.30 ROLLS ROYCE CORP
  • EP3372506B1 patent drawingFigure 1
  • EP3372506B1 patent drawingFigure 2
  • EP3372506B1 patent drawingFigure 3

AI summary

A propulsion system (10) that includes a plurality of power units (12A-N), a plurality of propulsors (14A-N), where respective power units of the plurality of power units are controllably coupled to the plurality of propulsors, and a controller (16) configured to receive a desired throttle value corresponding to a desired propulsive force, determine a number of power units of the plurality of power units to be coupled to the plurality of propulsors to achieve the desired propulsive force based on a respective power value associated with each respective power unit of the plurality of power units, and cause the number of power units of the plurality of power units to be coupled to the plurality of propulsors.