Electricity Generation System for Jet Engine Surge Margin Control

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Solution Overview

Problem

The increasing power demand in aircraft equipped with jet engines leads to reduced surge margin, increasing the possibility of compressor stall and unstable operation, as existing systems rely heavily on the high-pressure shaft for both mechanical and electrical power generation.

Innovation Solution

An electricity generation system utilizing both high-pressure and low-pressure shafts of the compressor, with a power control device regulating the ratio of power output between two electric generators to maintain a specified surge margin, ensuring stable operation and increased power supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If power output of the first electric generator (driven by high-pressure shaft) is increased to meet increasing power demand, then power supply capability is improved, but surge margin of the jet engine is reduced

Engineering Contradiction:
Improvepower supply capabilityVSAvoidsurge margin
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The electricity generation function is segmented into two independent generators: the first generator (21) driven by the high-pressure shaft and the second generator (22) driven by the low-pressure shaft. This segmentation allows power generation to be distributed across both shafts, reducing the load on the high-pressure shaft and maintaining surge margin while meeting power demand.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power control device (29) dynamically adjusts the power output ratio between the first and second generators based on real-time surge margin conditions and power demand. When surge margin is sufficient, the first generator provides more power; when surge margin is low, the second generator increases its output to relieve the high-pressure shaft load.

Inventive Principle:
Principle #15Dynamics

2Reliability

If power output ratio between first and second generators is dynamically adjusted to maintain surge margin, then jet engine operability is improved, but control system complexity is increased

Engineering Contradiction:
Improvejet engine operabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The power control device (29) implements a feedback control mechanism that continuously monitors surge margin conditions and power demand, then adjusts the power output ratio between the two generators accordingly. The controller receives input about current operating conditions and automatically modifies generator output to maintain optimal surge margin, creating a closed-loop control system that ensures engine operability.

Inventive Principle:
Principle #23Feedback

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 system effectively manages surge margin and power demand, reducing the likelihood of jet engine surge while maintaining stable operation by dynamically adjusting the power output of both electric generators based on load conditions, thereby enhancing the stability and efficiency of power generation.

Implementation Method 1

a first electric generator (21) designed to generate electricity by rotation of a high-pressure shaft (122) of a compressor (12)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a second electric generator (22) designed to generate electricity by rotation of a low-pressure shaft (121) of the compressor (12)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2657457B1Electricity generation system
Publication Date: 2020.06.10 IHI AEROSPACE CO LTD
  • EP2657457B1 patent drawingFigure 1
  • EP2657457B1 patent drawingFigure 2
  • EP2657457B1 patent drawingFigure 3

AI summary

An electricity generation system according to the present invention comprises a first electric generator (21) designed to generate electricity by rotation of a highpressure shaft (122) of a compressor (12) constituting a jet engine, a second electric generator (22) designed to generate electricity by rotation of a low-pressure shaft (121) of the compressor (12), a power distributor (28) for distributing power generated by the first and second electric generators (21, 22) among multiple loads, a first power regulation device (25) for regulating power output of the first electric generator (21), a second power regulation device (26) for regulating power output of the second electric generator (22), and a power control device (29) which manipulates the first and second power regulation devices (25, 26) to ensure a specified amount or greater of jet engine surge margin.