3D Magnetic Unit Structure for EV Wireless Charging Heat Dissipation

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Solution Overview

Problem

Conventional wireless charging devices for electric vehicles face issues with decreased efficiency due to heat generation and poor heat dissipation, leading to increased manufacturing costs and weight, as sintered ferrite sheets used for magnetic materials generate heat that is not effectively dissipated, affecting the magnetic properties and impedance mismatch.

Innovation Solution

A wireless charging device with a three-dimensional magnetic unit structure, comprising a first magnetic unit with a thicker outer part and thinner central part, and optionally additional magnetic units with varying magnetic permeability, to enhance charging efficiency and heat dissipation by distributing magnetic flux and dissipating heat effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sintered ferrite sheet is used as magnetic material adjacent to the coil, then magnetic properties are enhanced, but heat is generated and magnetic characteristics deteriorate due to poor heat dissipation

Engineering Contradiction:
Improvemagnetic propertiesVSAvoidheat generation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The magnetic unit is divided into multiple magnetic sheets arranged in a specific configuration. Each magnetic sheet has a thickness of 0.1mm or more but not exceeding 5mm, and multiple sheets are stacked with spacing between them. This segmentation allows heat to dissipate through the gaps between sheets while maintaining the necessary magnetic properties, preventing the heat accumulation that occurs in conventional single-thick ferrite sheets.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a conventional single-layer magnetic material configuration to a multi-layer stacked structure with spacing in the thickness dimension. By creating gaps between magnetic sheets along the thickness direction, heat dissipation pathways are introduced without compromising the magnetic flux distribution, effectively managing thermal characteristics while maintaining magnetic performance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the distance between the coil and metal plate is reduced to enhance charging efficiency, then charging efficiency improves, but heat generation increases and magnetic characteristics change

Engineering Contradiction:
Improvecharging efficiencyVSAvoidheat generation
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

Different regions of the magnetic unit have different structures optimized for their specific functions. The magnetic sheets are positioned at specific distances from the coil, with each sheet having controlled thickness (0.1mm to 5mm) and spacing from adjacent sheets. This local structural variation allows the magnetic field to be effectively coupled at close distances for high charging efficiency while the spaced configuration provides localized heat dissipation zones where heat can escape without causing overall temperature rise.

Inventive Principle:
Principle #3Local quality

3Reliability

If a sealed structure is adopted for dustproofing and waterproofing, then protection is improved, but heat dissipation becomes difficult

Engineering Contradiction:
Improveprotection from dust and waterVSAvoidheat dissipation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The magnetic unit employs a porous or spaced configuration where multiple magnetic sheets are separated by gaps. These gaps create internal void spaces that facilitate heat circulation and dissipation. The sealed housing can incorporate heat dissipation pathways that utilize these internal spaces, allowing heat to escape through controlled channels while maintaining the sealed protection against dust and water ingress.

Inventive Principle:
Principle #31Porous materials

4Reliability

If conventional magnetic materials are used, then magnetic properties are maintained, but manufacturing cost and weight increase

Engineering Contradiction:
Improvemagnetic propertiesVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

Instead of using a single thick magnetic material block, the invention segments the magnetic unit into multiple thin sheets (each 0.1mm to 5mm thick). This segmentation reduces the total weight compared to a solid block of equivalent overall thickness, while the stacked configuration with spacing maintains the necessary magnetic flux pathways. The reduced weight directly addresses the burden on the vehicle without sacrificing magnetic functionality.

Inventive Principle:
Principle #1Segmentation

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 three-dimensional structure improves charging efficiency and heat dissipation characteristics, reducing heat generation and manufacturing costs while maintaining stability and impact resistance, suitable for electric vehicles requiring large-capacity power transmission.

Implementation Method 1

The wireless power transmission refers to wirelessly transmitting power through space using inductive coupling, capacitive coupling, or an electromagnetic field resonance structure such as an antenna

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a magnetic material is disposed adjacent to the coil to enhance the wireless charging efficiency

Methodology Applied
Scientific EffectMagnetic flux concentration: Magnetic Field

Implementation Method 3

A wireless charging device generates heat due to the resistance of a coil and the magnetic loss of a magnetic material during the wireless charging operation

Methodology Applied
Scientific EffectMagnetic loss: Magnetic Hysteresis

Implementation Method 4

the outer part has a thickness greater than the thickness of the central part... the three-dimensional structure improves charging efficiency and heat dissipation characteristics

Methodology Applied
Scientific EffectHeat dissipation: Convection

Data Source

PatentEP4053864B1Wireless charging apparatus and mobile means comprising same
Publication Date: 2025.08.20 SKC CO LTD
  • EP4053864B1 patent drawingFigure 1
  • EP4053864B1 patent drawingFigure 2a~2c
  • EP4053864B1 patent drawingFigure 3

AI summary

A wireless charging apparatus according to an embodiment may improve both the charging efficiency and the heat dissipation characteristics by use of a three-dimensional structure in a magnetic portion. In detail, the wireless charging efficiency may be increased and heat generated from the magnetic portion may be lowered by increasing the thickness of the magnetic portion near a coil portion, where electromagnetic energy is concentrated during wireless charging, and by reducing the thickness of the magnetic portion in the center, where the density of the electromagnetic energy is relatively low. Accordingly, the wireless charging apparatus can be efficiently used in a mobile means such as an electric vehicle that requires transmission of a large amount of power between a transmitter and a receiver.