Aircraft Starter/Generator AC DC Mode Selection

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Solution Overview

Problem

Current starter/generator systems for aircraft require multiple power conversion stages and active rectification, which increase weight, size, and complexity, limiting efficiency and reliability in starting and generating modes.

Innovation Solution

A method that selectively starts at least one starter/generator in AC or DC mode using an inverter/converter system, bypassing unnecessary conversion stages, allowing direct power supply from AC or DC sources to the starter/generators, reducing the need for intermediary power conversion components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple power conversion stages and active rectification are used in starter/generator systems, then the system can operate in both starting and generating modes, but the weight, size, and complexity of the system increase

Engineering Contradiction:

Improveoperational mode flexibilityVSAvoidpower conversion stages

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The starter/generator is designed as a universal machine that can operate in multiple modes (starting mode and generating mode) using the same core components. The system uses the starter/generator both as an electric motor during engine starting and as an electric generator during power generation, eliminating the need for separate motors and generators.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent extracts and eliminates unnecessary power conversion stages from the system. By using the starter/generator directly in both motor and generator modes, the system removes redundant converters and rectifiers that would otherwise be needed to interface between different power sources and the starter/generator.

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

Engineering Contradiction:

Improveoperational mode flexibilityVSAvoidsystem weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The starter/generator serves dual purposes as both motor and generator, eliminating the need for separate heavy components. This multi-functionality reduces overall system weight while maintaining operational flexibility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

By removing unnecessary power conversion stages and rectification components, the system significantly reduces weight. The direct connection of the starter/generator to power sources eliminates heavy intermediary conversion equipment.

Inventive Principle:

Principle #2Taking out (Extraction)

3Adaptability or versatility

If unnecessary conversion stages are used, then power can be supplied through multiple pathways, but the number of components and system complexity increase

Engineering Contradiction:

Improvepower supply flexibilityVSAvoidnumber of components

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent removes unnecessary conversion stages and intermediary components from the power supply pathway. By using the starter/generator directly with AC or DC sources, the system maintains power supply flexibility while minimizing the quantity of components.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of converting all power sources to a single intermediate form, the system inverts the approach by allowing direct connection of different power sources (AC or DC) to the starter/generator, eliminating the need for multiple conversion stages.

Inventive Principle:

Principle #13The other way round (Inversion)

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 approach reduces the number of active rectification stages, eliminates redundant components, and provides a robust, lightweight, and reliable electrical starting system capable of starting aircraft using various power sources, enhancing efficiency and reducing maintenance costs.

Implementation Method 1

the DC power output to an inverter/converter, which transforms the DC power output to an AC power output

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS9810155B2Method for starting aircraft engines

Publication Date: 2017.11.07 GE AVIATION SYSTEMS LLC

AI summary

A method of starting an aircraft having at least a first starter/generator (S/G) and a second S/G using at least one inverter/converter and at least one of an AC power source and a first DC power source, the method includes selectively starting at least one of the first S/G or second S/G in an AC start mode and in a DC start mode.