Dual PMG Start Control Using Sensorless Rotor Position Detection

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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 while improving sensing precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional resolvers are used for rotor position sensing, then the system can obtain rotor position information, but the system reliability deteriorates due to harsh environmental conditions causing mechanical failures

Engineering Contradiction:
Improverotor position sensing accuracyVSAvoidsystem reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical resolver system with an electrical field-based sensing system. The sensorless control system uses electrical signals and mathematical algorithms to determine rotor position without mechanical moving parts, thereby eliminating the mechanical failures inherent in traditional resolvers while maintaining position sensing accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary sensorless control system that acts as a mediator between the motor and the control unit. This intermediary system processes electrical signals and computes rotor position information without direct mechanical contact, improving reliability while preserving measurement precision

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If traditional resolvers are used for rotor position sensing, then the system can determine rotor position, but the system cost increases due to expensive resolver components

Engineering Contradiction:
Improverotor position sensing accuracyVSAvoidsystem cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent employs cost-effective electrical sensing components and algorithms that replace expensive mechanical resolvers. The sensorless control system uses standard electrical sensors and computational methods that are significantly cheaper than traditional resolver assemblies, reducing overall system cost while maintaining positioning accuracy

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

By substituting the expensive mechanical resolver system with an electrical field-based sensorless control system, the patent eliminates the need for costly mechanical components, thereby reducing manufacturing costs while preserving the ability to accurately determine rotor position

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If traditional resolvers are used for rotor position sensing, then the system can obtain position data, but the system weight increases due to additional mechanical components

Engineering Contradiction:
Improverotor position sensing accuracyVSAvoidsystem weight
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent replaces heavy mechanical resolver components with lightweight electrical sensing elements and computational algorithms. This substitution eliminates the need for mechanical moving parts, sensors, and associated mounting structures, significantly reducing system weight while maintaining rotor position sensing accuracy

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the heavy mechanical resolver components from the system, retaining only the essential electrical sensing and computational functions. This extraction eliminates unnecessary weight while preserving the core functionality of accurate rotor position determination

Inventive Principle:
Principle #2Taking out (Extraction)

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 enhances the reliability and precision of rotor position sensing, reducing mechanical failures and costs, and improves the overall performance of the EPGSS by accurately determining rotor position without the need for resolvers.

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 EffectSensorless position detection through coordinate transformation:

Data Source

PatentEP4290757A1Main engine start using a dual permanent magnet generator system
Publication Date: 2023.12.13 HAMILTON SUNDSTRAND CORP
  • EP4290757A1 patent drawingFigure 1
  • EP4290757A1 patent drawingFigure 2
  • EP4290757A1 patent drawingFigure 3

AI summary

An aircraft electric power generation and start system (EPGSS) includes a main machine (110), a starter permanent magnet generator (PMG) (102), a generator PMG (104), and a carrier injection sensorless (CIS) system (304). The main machine selectively operates in a start mode or a generator mode. The starter PMG includes a first PMG stator (50a) and a first PMG rotor (52a) and is configured to rotate along with the shaft (101). The generator PMG includes a second PMG stator (50b) and a second PMG rotor (52b) 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.