Stator-Integrated Rotor Sensing in Aircraft Electrical Machines
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Solution Overview
Problem
Existing electrical machines in aircraft propulsion systems face challenges in accurately monitoring rotor position, particularly at low speeds and low loads, and are hindered by the use of costly and bulky shaft-mounted sensors, as well as unreliable sensorless control methods.
Innovation Solution
An electrical machine design with integrated sensors in the stator, where each phase is grouped into elementary blocks, and sensors are positioned between these blocks to measure rotor parameters, including position and temperature, without the need for rotating sensors, thereby reducing weight and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate bearings are used for rotor support and damper driving, then reliable rotor support is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the rotor support bearing and damper driving bearing into a single integrated bearing structure. The bearing is designed with an inner ring that has a first portion supporting the rotor and a second portion driving the damper, eliminating the need for separate bearings while maintaining both functions reliably
Solution Approach 2:
The single bearing structure performs multiple functions simultaneously: it supports the rotor radially and axially while also providing the driving force for the damper winding through its second portion. This multi-functional design reduces component count and simplifies the overall machine structure
2Adaptability or versatility
If separate windings are used for rotor and damper, then independent control is achieved, but manufacturing precision and assembly difficulty increase
Solution Approach 1:
The patent combines the rotor winding and damper winding into a single integrated winding structure called the 'damper winding' that serves both purposes. The winding is constructed with multiple bars that can function as either rotor conductors or damper conductors depending on their connection configuration, eliminating the need for separate windings
Solution Approach 2:
The winding structure is designed to be dynamically configurable, where the same physical winding can be electrically connected to provide rotor function during normal operation and damper function during transient conditions. This dynamic reconfiguration capability allows independent control while using a single static physical structure
3Temperature
If complex cooling channels are used, then cooling efficiency is improved, but manufacturing complexity and pressure loss increase
Solution Approach 1:
The patent implements cooling channels with varying cross-sectional areas at different locations along the stator core. The channel cross-section is larger near the cooling inlet and gradually reduces toward the outlet, optimizing the cooling flow distribution locally at each position to improve overall cooling efficiency while maintaining simple channel geometry
Solution Approach 2:
The cooling channel design changes the geometric parameter (cross-sectional area) along the flow direction to optimize cooling performance. By gradually reducing the channel cross-section from inlet to outlet, the system maintains efficient heat removal without requiring complex channel configurations or additional components
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
This design provides accurate rotor position and temperature measurement, enhances fault tolerance, and reduces overall machine weight and cost by integrating sensors within the stator, ensuring robust performance across varying operational conditions.
Implementation Method 1
the stator of the electrical machine has a stator winding and the rotor has a rotor winding, in such a way that the stator winding and the rotor winding together form a doubly-fed machine
Data Source
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AI summary
An electrical machine for use in an aircraft, comprising a rotor, wherein the rotor comprises a plurality of rotor poles, and a stator comprising a plurality of phases, wherein each respective phase occupies at least one elementary block, the at least one elementary block of each phase comprising a set of conductors of the respective phase wound around a plurality of slots of the respective elementary block in a concentrated winding configuration, wherein the stator further comprises at least one sensor located between two elementary blocks, the at least one sensor being configured to measure at least one parameter of the rotor.