Magnetic Characterization of Spirally Wrapped Induction Heating Wires

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Solution Overview

Problem

Magnetic characterization of spirally wrapped induction heating wires is challenging due to the inability of existing equipment like the Epstein frame to provide precise measurements, and it fails to account for changes in magnetic properties caused by the winding process, which affects the control of heat generation in induction heating assemblies.

Innovation Solution

A system and method involving a conductor with a spirally wrapped induction heating wire, an alternating current power source, current and voltage sensors, and a sensing wire arranged in loops to accurately measure the magnetic response of the induction heating wire by isolating its magnetic field from the conductor's field, allowing for precise characterization and control of heat generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an Epstein frame is used to characterize induction heating wires, then magnetic properties can be measured, but the measurement precision is insufficient for spirally wrapped wires

Engineering Contradiction:
Improvemagnetic characterization precisionVSAvoidapplicability to spirally wrapped wires
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The sensing wire is divided into multiple segments arranged in a specific geometric pattern (e.g., hexagonal or circular arrangement with central and peripheral sensing wires). This segmentation allows the system to isolate and measure the magnetic field contribution of the induction heating wire separately from the conductor's magnetic field, enabling precise characterization of spirally wrapped wires that traditional Epstein frames cannot handle.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple sensing wires are positioned between the conductor and the induction heating wire to detect the magnetic field. These intermediary sensing wires measure the combined magnetic field, which is then processed to extract the specific magnetic properties of the induction heating wire, achieving precise measurement in a configuration that accommodates spirally wrapped wires.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If magnetic characterization is performed on the induction heating wire before winding, then measurement can be conducted, but changes due to work hardening from the winding process are not accounted for

Engineering Contradiction:
Improveease of magnetic characterizationVSAvoidaccuracy of magnetic properties in final application
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The magnetic characterization system is designed to perform measurements after the winding process is complete. The sensing wires are positioned to detect the magnetic field of the induction heating wire in its final spirally wrapped configuration, ensuring that the measured magnetic properties reflect the actual state of the wire during operation, including any work hardening effects from the winding process.

Inventive Principle:
Principle #10Preliminary action

3Power

If the induction heating wire is positioned in close proximity to the conductor, then heating efficiency is improved, but the magnetic field from the conductor interferes with measurement

Engineering Contradiction:
Improveheating efficiencyVSAvoidmagnetic field measurement accuracy
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

Sensing wires are positioned at specific locations in the magnetic field - some between the conductor and induction heating wire, and others arranged in patterns (hexagonal, circular) at defined distances. This localized positioning allows measurement of the magnetic field contribution from the induction heating wire while accounting for the conductor's field, maintaining both close proximity for efficient heating and measurement accuracy.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sensing wire arrangement uses asymmetric positioning relative to the conductor and induction heating wire, with sensing wires placed at different radial distances and angular positions. This asymmetric configuration enables differentiation between the magnetic fields of the conductor and the induction heating wire, allowing precise measurement even when the induction heating wire is in close proximity to the conductor for optimal heating efficiency.

Inventive Principle:
Principle #4Asymmetry

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

Enables precise magnetic characterization of spirally wrapped induction heating wires, accounting for changes due to the winding process, thereby allowing for controlled heat generation in induction heating applications.

Implementation Method 1

induction heating assemblies employ electromagnetic induction to generate heat

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

heats the induction heating wire by way of eddy currents and magnetic hysteresis

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Implementation Method 3

heats the induction heating wire by way of eddy currents and magnetic hysteresis

Methodology Applied
Scientific EffectMagnetic hysteresis: Magnetic Hysteresis

Implementation Method 4

a sensing wire including a first lead and an opposed second lead, wherein the sensing wire defines a first loop having a first polarity and a second loop having a second, opposite polarity

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS9995799B2System and method for magnetic characterization of induction heating wires
Publication Date: 2018.06.12 THE BOEING CO

AI summary

A system for magnetic characterization of an induction heating wire including a conductor having a first end and a second end longitudinally opposed from the first end, wherein the induction heating wire extends along a portion of the conductor and is electrically isolated from the conductor, an alternating current power source electrically coupled with the conductor to pass an electric current between the first end and the second end, a current sensor positioned to sense the electric current, a sensing wire including a first lead and an opposed second lead, wherein the sensing wire defines a first loop having a first polarity and a second loop having a second, opposite polarity, the second loop being connected to the first loop at a crossover, and wherein the induction heating wire extends through the first loop, and a voltage sensor positioned to sense a voltage across the first lead and the second lead.