Flux-Switching Machine Embedded in Aircraft Engine Core
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Solution Overview
Problem
Existing aircraft engine generator systems face challenges due to extreme temperature, vibration, and rotational speed environments, leading to complex packaging and reliability issues, particularly when embedding generators into the engine core, as traditional machines like wound field synchronous, permanent magnet, switch reluctance, and induction machines require significant space, structural support, and power conditioning, resulting in increased weight and size.
Innovation Solution
A flux-switching machine is embedded within the aircraft engine, featuring a brushless design with a rotor and stator having different numbers of poles, a field winding set that can be shut down in case of faults, and armature windings that generate three-phase AC power, allowing for simplified packaging and fault tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional wound field synchronous machines are embedded in the engine, then power generation capability is achieved, but packaging complexity and device size increase
Solution Approach 1:
The machine is divided into two independent winding sets (first and second windings) that can operate separately or together, allowing modular packaging and simplified integration into the engine architecture
Solution Approach 2:
The generator machine serves multiple functions: it can generate power using either winding independently or both windings combined, and can operate across different speed ranges by switching between windings, eliminating the need for separate systems
2Device complexity
If permanent magnet machines are used, then machine construction is simplified, but structural support requirements and weight increase
Solution Approach 1:
The patent uses conventional windings instead of expensive permanent magnets, accepting that the windings may require replacement over time but eliminating the need for heavy structural support structures required for magnet retention
Solution Approach 2:
The patent replaces the mechanical permanent magnet field with an electromagnetic field generated by windings, eliminating the need for mechanical structural support to retain magnets while achieving the same magnetic field function
3Temperature
If switch reluctance machines are employed, then high speed and temperature operation is enabled, but power conditioning requirements and system weight increase
Solution Approach 1:
The patent replaces the complex power conditioning electronics of switch reluctance machines with a conventional wound field design that naturally produces sinusoidal back-EMF, eliminating heavy power electronics while maintaining high temperature operation capability through proper insulation and cooling
Solution Approach 2:
The patent changes the operating parameters by using windings that can be independently controlled to optimize performance across different temperature and speed ranges, eliminating the need for additional power conditioning equipment
4Volume of moving object
If generators are embedded in the engine core, then external size is reduced, but reliability requirements become more difficult to meet
Solution Approach 1:
The generator is segmented into independent winding sets that can operate independently, so if one winding fails due to extreme conditions, the other can continue operating, maintaining reliability while keeping the embedded size compact
Solution Approach 2:
The dual winding design provides built-in redundancy before failures occur, allowing the system to withstand extreme temperature and vibration conditions in the engine core with enhanced reliability
5Adaptability or versatility
If variable speed operation is implemented, then speed range adaptability is improved, but machine packaging complexity increases
Solution Approach 1:
The patent implements dynamic speed range adaptation by switching between two windings with different turns ratios, allowing the machine to maintain optimal performance across a wide speed range without complex mechanical variable speed mechanisms
Solution Approach 2:
The dual winding design provides universal operation across multiple speed ranges, with each winding optimized for different operational regimes, eliminating the need for separate machines or complex variable speed packaging
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 flux-switching machine simplifies engine packaging, reduces weight, and enhances reliability by providing high power density and fault-tolerant three-phase AC power generation, eliminating the need for external gearboxes and power electronics, while maintaining performance across varying speed ranges.
Implementation Method 1
a field winding set that can be shut down in case of faults
Implementation Method 2
armature windings that generate three-phase AC power
Data Source
Figure 1
Figure 2
AI summary
An aircraft engine assembly includes an engine housing 32, a low pressure spool 24 disposed within the engine housing, and a high pressure spool 26 disposed within the engine housing. Also included is a flux-switching machine 40 disposed within the engine housing, the flux-switching machine comprising a rotor 42, a stator 44, a field winding 50 and an armature winding 52, the flux-switching machine configured to generate power for the aircraft power system. Also provided is a method of generating electric energy for an aircraft power system. The method includes energizing a field winding set of a flux-switching machine disposed entirely within an engine housing of the aircraft engine. The method also includes outputting electrical energy to an electrical system of the aircraft with a three phase armature winding of the flux-switching machine to provide electrical power to at least one aircraft component.