Aircraft Power Chain Pre-Flight Testing via Low Voltage Stimuli

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Solution Overview

Problem

Current systems do not allow for effective pre-flight testing of aircraft components powered by the 115V AC network, leading to potential catastrophic malfunctions during landing due to undetected failures in the electronic power system of thrust reverser actuators and other components.

Innovation Solution

A testability method that generates stimuli in the electronic power chain to check the availability of components without actuating the electric motor, using low voltage signals and existing sensors to detect faults like short-circuits or open-circuits, allowing pilots to assess system functionality before landing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the 115V AC network is made available only when the aircraft touches the ground, then inadvertent actuation in flight is prevented, but pre-flight testing of the electronic power chain becomes impossible

Engineering Contradiction:
Improveprevention of inadvertent actuationVSAvoidtesting capability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by enabling testing of the electronic power chain before the aircraft lands. The testability device is activated during the approach phase to verify the functionality of the 115V AC network and associated components (rectifier, inverter, motor) before they are needed for thrust reverser operation, allowing detection of potential failures prior to landing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary testability device that mediates between the restricted 115V AC network and the testing requirements. This device includes a low-voltage power supply (28V DC) that can stimulate the electronic power chain components without requiring full 115V AC power, enabling safe testing during approach while maintaining the restriction on full power availability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the electronic power chain is isolated from nominal supply during testing, then safety is improved, but testing complexity increases

Engineering Contradiction:
Improvetesting safetyVSAvoidtesting system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the testing function into separate components: a testability device with low-voltage power supply, switching means for isolation, and control logic. This segmentation allows the testing function to be added without modifying the main 115V AC power distribution system, maintaining safety through electrical isolation while managing complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The switching means acts as an intermediary that physically isolates the electronic power chain from the nominal 115V AC supply during testing. This intermediary component enables safe testing by preventing dangerous voltage levels from reaching the components under test, while the control means coordinates the isolation and testing sequences to manage operational complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3635423B1Testing method for an electronic power chain associated with an electric motor
Publication Date: 2023.04.12 SAFRAN NACELLES
  • EP3635423B1 patent drawingFigure 1~2
  • EP3635423B1 patent drawingFigure 3~4
  • EP3635423B1 patent drawingFigure 5~6

AI summary

The present invention relates to a testability method (500) for the in-flight testing of an operating state (540) of an electronic power chain (100) comprising at least one power converter intended for driving an electric motor (300). The electric motor (300) actuating at least one aircraft component; the testability method (500) comprising steps of controlling the actuation (510) of the converter, of transmitting (520) a test signal (140), of collecting (530) at least one measurement signal (150) and of determining (540) an operating state (540).