Electric Vehicle Underbody Shielding for Wireless Power Resonance

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Solution Overview

Problem

The use of non-contact resonance-based power transfer for electric vehicles generates high-frequency electromagnetic waves that can adversely affect the vehicle's electric equipment.

Innovation Solution

The power receiving resonator and power cable are positioned under a metal underbody, which shields the electromagnetic waves, preventing them from affecting the vehicle's internal equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If non-contact resonance-based power transfer is used to charge the vehicle, then power transfer efficiency and convenience are improved, but electromagnetic waves are generated that adversely affect the vehicle's electric equipment

Engineering Contradiction:
Improvepower transfer efficiencyVSAvoidelectromagnetic wave interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The vehicle body is segmented into an upper portion (containing electric equipment) and a lower portion (containing the power receiving resonator), separated by the metal underbody. This spatial segmentation isolates the harmful electromagnetic waves generated during resonance-based power transfer from the sensitive electric equipment, allowing efficient wireless charging while protecting against interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The metal underbody acts as an intermediary shielding structure between the power receiving resonator and the vehicle's electric equipment. It absorbs and blocks electromagnetic waves generated during resonance-based power transfer, preventing them from reaching sensitive components while allowing the power transfer system to operate efficiently.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the power receiving resonator is positioned inside the vehicle for easy connection, then ease of operation is improved, but electromagnetic waves directly affect the electric equipment

Engineering Contradiction:
Improveconnection convenienceVSAvoidelectromagnetic wave interference
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The power receiving resonator is positioned in the lower dimension (under the vehicle body) rather than inside the upper dimension (vehicle cabin). This dimensional relocation places the resonator below the metal underbody, which acts as a shield, thereby protecting the electric equipment in the upper dimension from electromagnetic wave interference while maintaining operational convenience through external ground connection.

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

3Object-affected harmful factors

If a metal underbody is added for electromagnetic shielding, then protection against electromagnetic waves is improved, but vehicle weight increases

Engineering Contradiction:
Improveelectromagnetic wave shieldingVSAvoidvehicle weight
Core Design Contradiction:
Object-affected harmful factorsVSWeight of moving object

Solution Approach 1:

The metal underbody serves multiple functions: it provides structural support for the vehicle, protects against corrosion and road debris, and acts as an electromagnetic shield during resonance-based power transfer. By making the underbody multi-functional, additional shielding components are avoided, minimizing weight increase while achieving comprehensive protection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The electromagnetic shielding effectiveness is optimized by adjusting parameters of the existing metal underbody (such as material composition, thickness, and ground connection configuration) rather than adding separate shielding structures. This parameter optimization achieves effective electromagnetic wave blocking with minimal additional weight.

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

This configuration effectively suppresses the adverse effects of electromagnetic waves on the vehicle's electric equipment during power reception, ensuring safer operation.

Implementation Method 1

resonance is a technique for causing a pair of resonators (e.g., a pair of self-resonant coils) to resonate with each other in an electromagnetic field (near field) to transfer power in a non-contact manner

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 2

Power transfer using electromagnetic induction, power transfer using a microwave, and power transfer by resonance are known as dominant techniques for wirelessly transferring power

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

Since the power receiving resonator is provided under the underbody made of metal, an electromagnetic wave generated around the power receiving resonator due to the reception of high-frequency power is shielded by the underbody

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP2407338B1Electric vehicle
Publication Date: 2020.04.29 TOYOTA JIDOSHA KK
  • EP2407338B1 patent drawingFigure 1~2
  • EP2407338B1 patent drawingFigure 3
  • EP2407338B1 patent drawingFigure 4~5

AI summary

An electrically powered vehicle (1) is capable of traveling with power supplied from a power feeding apparatus outside of the vehicle. A power receiving resonator (20) is provided under an underbody (10) made of metal, and configured to receive power from a power transferring resonator (60) of the power feeding apparatus by resonating with the power transferring resonator (60) through an electromagnetic field. A power storage device (40) stores the power received by the power receiving resonator (20). A power cable (30) is provided under the underbody (10) together with the power receiving resonator (20), and configured to transfer the power received by the power receiving resonator (20) to the power storage device (40).