Dual PMG Rotor Position Sensing for Aircraft Engine Start

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Solution Overview

Problem

Traditional aircraft electric power generation and start systems (EPGSSs) rely on expensive and unreliable resolvers for rotor position sensing, which fail due to harsh environmental conditions, leading to mechanical failures and reduced accuracy.

Innovation Solution

The implementation of a dual-PMG system with a carrier injection sensorless (CIS) system that determines rotor position using multiphase coordinates and alpha-beta coordinates, eliminating the need for physical resolvers and reducing costs and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional resolvers are used for rotor position sensing, then rotor position can be determined, but the system becomes expensive and unreliable due to harsh environmental conditions

Engineering Contradiction:

Improverotor position sensing reliabilityVSAvoidrotor position sensing accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical resolver system with an electronic sensorless control system using a permanent magnet generator (PMG). The PMG generates electrical signals that are processed by a controller to determine rotor position without mechanical contact, eliminating the reliability issues of resolvers in harsh environments while maintaining measurement precision through electronic signal processing

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a permanent magnet generator as an intermediary component between the rotor and the control system. The PMG converts mechanical rotation into electrical signals that carry rotor position information, serving as a mediator that enables accurate position sensing without the drawbacks of direct resolver measurement in harsh conditions

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If resolvers are used for rotor position sensing, then rotor position can be determined, but the system weight and cost increase

Engineering Contradiction:

Improverotor position sensing accuracyVSAvoidsystem weight

Core Design Contradiction:

Measurement precisionVSWeight of stationary object

Solution Approach 1:

The patent replaces the heavy mechanical resolver assembly with a lightweight electronic PMG system. The PMG uses electromagnetic fields rather than mechanical components to sense rotor position, dramatically reducing system weight while maintaining measurement precision through electronic signal processing

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a cost-effective PMG system that eliminates expensive resolver components. The electronic sensors and control circuitry in the PMG system are more economical than traditional resolver assemblies, reducing overall system cost while achieving the same measurement function

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If resolvers are used for rotor position sensing, then rotor position can be determined, but the system complexity increases

Engineering Contradiction:

Improverotor position sensing accuracyVSAvoidsensing system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the complex mechanical resolver system with a simpler electronic PMG system. The electronic sensors and digital signal processing in the PMG system reduce mechanical complexity while achieving equivalent or superior measurement precision through software-based position calculation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution improves rotor sensing precision and reliability while reducing costs and weight, providing accurate rotor position determination in both generator and start modes without the limitations of traditional resolver-based systems.

Implementation Method 1

The starter PMG includes a first PMG stator, and a first PMG rotor configured to rotate along with the shaft... The generator PMG includes a second PMG stator and a second PMG rotor configured to rotate along with the shaft

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The CIS system is configured to determine one or both of a PMG voltage and a PMG current corresponding to the first PMG during the start mode, and to determine a rotational position of the main rotor based on one or both of the PMG voltage and the PMG current

Methodology Applied

Scientific EffectSignal processing and harmonic analysis:

Data Source

PatentUS11927102B2Main engine start using a dual permanent magnet generator system

Publication Date: 2024.03.12 HAMILTON SUNDSTRAND CORP

AI summary

An aircraft electric power generation and start system (EPGSS) includes a main machine, a starter permanent magnet generator (PMG), a generator PMG, and a carrier injection sensorless (CIS) system. The main machine selectively operates in a start mode or a generator mode. The starter PMG includes a first PMG stator and a first PMG rotor and is configured to rotate along with the shaft. The generator PMG includes a second PMG stator and a second PMG rotor configured to rotate along with the shaft. The CIS system determines one or both of a PMG voltage and a PMG current corresponding to the first PMG during the start mode, and determines a rotational position of the main rotor based on one or both of the PMG voltage and the PMG current.