Wireless Power Magnetic Core Structure for Coil Misalignment

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Solution Overview

Problem

Existing inductive wireless power transfer systems for electric vehicles face challenges in maintaining efficient power transfer due to deviations in power transfer distance and coil alignment between the primary and secondary coils.

Innovation Solution

A magnetic core structure with two wall-shaped structures is introduced, which is positioned to maximize separation within the space surrounded by the primary coil. This structure adjusts the mutual inductance and coupling coefficient between the coils, enhancing power transfer efficiency even in misaligned states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple inductive wireless power transfer arrangement is used, then the device complexity is reduced, but the power transfer efficiency deteriorates when there is deviation in power transfer distance or coil alignment

Engineering Contradiction:

Improvestructure simplicityVSAvoidpower transfer efficiency

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

A magnetic core structure is introduced as an intermediary component between the primary coil and secondary coil. This magnetic core includes a first core and a second core extending in the power transfer direction, which mediate the magnetic field coupling between the coils. The magnetic core maintains stable magnetic flux distribution even when there is deviation in power transfer distance or coil alignment, thereby maintaining power transfer efficiency without significantly increasing device complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the power transfer distance between primary coil and secondary coil is increased, then the degree of freedom in power transfer range is improved, but the coupling coefficient and power transfer efficiency deteriorate

Engineering Contradiction:

Improvepower transfer rangeVSAvoidpower transfer efficiency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The magnetic core structure extends in the power transfer direction (vertical dimension) between the primary and secondary coils. By adding this vertical dimensional element, the magnetic flux path is established and maintained even when horizontal alignment or vertical distance varies. This dimensional addition allows the system to tolerate larger variations in power transfer distance while maintaining efficient coupling.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of operation

If coil alignment between primary coil and secondary coil is relaxed, then the ease of operation is improved, but the mutual inductance and power transfer efficiency deteriorate

Engineering Contradiction:

Improvecoil alignment toleranceVSAvoidpower transfer efficiency

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The magnetic core structure changes the magnetic circuit parameters by providing a dedicated flux path with high magnetic permeability. This parameter change in the magnetic circuit allows the system to maintain high mutual inductance even when coil alignment is not perfect. The magnetic core effectively decouples the mutual inductance from strict alignment requirements, enabling easier operation while maintaining efficiency.

Inventive Principle:

Principle #35Parameter changes

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

The proposed magnetic core structure increases the degree of freedom in power transfer distance and coil alignment, significantly improving power transfer efficiency across various misalignment positions within a maximum available misalignment range.

Implementation Method 1

Methodology Applied

Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

the magnetic core with the wall-shaped structures is disposed at a maximum available misalignment position to increase the coupling coefficient at misaligned positions without reducing the coupling coefficient at an aligned position

Methodology Applied

Scientific EffectMagnetic Field: Magnetic Field

Data Source

PatentEP4572088A1Magnetic core structure for wireless power transfer, and wireless power transfer device and method using core structure

Publication Date: 2025.06.18 HYUNDAI MOTOR CO LTD

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AI summary

A magnetic core structure provided together with a primary coil for wireless power transfer (WPT) includes: a first structure which has a structure extending in a first axis direction in a first area including the center of the primary coil and protrudes therefrom; a second structure which is spaced apart from the first structure in a second axis direction, has a structure extending in the first axis direction, and protrudes therefrom; and a support structure which has the same magnetic characteristic as the first structure and the second structure and supports the first structure and the second structure.