Double Dipole Inductive Charging Loops for EVs

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Solution Overview

Problem

Existing inductive charging systems for electric vehicles face challenges in efficiently transmitting electrical energy while traveling while adhering to maximum permissible EMF limits, resulting in lengthy charging sections and high costs.

Innovation Solution

The implementation of a device with primary conductor loop units arranged as double dipole loops, featuring branched feed lines and non-branching return lines, along with a registration device for vehicle localization, allows for efficient energy transfer by maintaining constant inductivity and reducing electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If inductive charging is used to charge electric vehicles while traveling, then charging time is reduced and convenience is improved, but electromagnetic interference fields increase and may exceed permissible EMF limits

Engineering Contradiction:
Improvecharging timeVSAvoidelectromagnetic interference fields
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The patent applies the principle of converting harmful electromagnetic fields into beneficial effects by using resonant frequency coupling. The primary and secondary coils are tuned to the same resonant frequency, which enhances the magnetic coupling between them. This resonance effect allows for efficient energy transfer at lower field strengths, thereby reducing the harmful electromagnetic interference while maintaining effective charging. The harmful high-frequency fields are converted into useful resonant magnetic coupling that enables wireless power transfer at acceptable EMF levels.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the operating parameters of the inductive charging system by tuning the resonant frequency of both primary and secondary coils to match. This parameter adjustment optimizes the magnetic coupling coefficient and allows the system to operate efficiently at lower power levels, thereby reducing electromagnetic interference. The resonant frequency parameter is specifically selected to maximize energy transfer while minimizing harmful EMF emissions to comply with permissible limits.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If conventional inductive charging systems are used, then wireless charging is achieved, but the required charging section length increases and costs rise

Engineering Contradiction:
Improvewireless charging capabilityVSAvoidcharging section length
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The patent employs resonant oscillation at specific frequencies to enhance the magnetic coupling between primary and secondary coils. This vibrational resonance creates a strong magnetic field coupling that maintains efficient energy transfer over shorter distances. By utilizing this resonant mechanical vibration principle in the electrical domain, the system achieves effective wireless charging with reduced charging section length compared to conventional inductive systems.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The system uses periodic alternating current at resonant frequency to generate the magnetic field for wireless power transfer. This periodic action at optimized frequency and amplitude creates sustained magnetic coupling that enables efficient charging over shorter road sections. The periodic switching and resonant oscillation allow the system to maintain effective power transfer with reduced infrastructure length.

Inventive Principle:
Principle #19Periodic action

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 solution shortens charging time, reduces section length and costs, and enhances energy transmission efficiency, enabling electric vehicles to recharge effectively during travel while minimizing adverse electromagnetic effects.

Implementation Method 1

at least one primary conductor loop unit (8), for magnetically coupling to a secondary conductor loop unit (7) arranged on an electric vehicle (1) for charging the at least one electrical energy store (22) via the circulating electrical voltage generated by means of induction in the secondary conductor loop unit (7)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2709871B1Device for inductively charging at least one electric energy store of an electric vehicle
Publication Date: 2020.02.12 BRUSA ELEKTRONIK AG
  • EP2709871B1 patent drawingFigure 1
  • EP2709871B1 patent drawingFigure 2a~2c
  • EP2709871B1 patent drawingFigure 2b

AI summary

The invention relates to systems, devices, and components for inductively charging an electric energy store of an electric vehicle (1) via a charging section (2). The device includes a registration device (20) for localizing the electric vehicle (1) on the charging section (2), an electrical energy source (3) preferably embodied as a high-frequency-energy source, a system of primary conductor loops each with at least one primary winding provided in the charging section (2) for supplying AC current via the electrical energy source (3), a secondary conductor loop arranged on the electric vehicle (1) having at least one secondary winding at least partially permeated by the induction flux, an energy supply line (4),and switching devices (5) for connecting the energy supply line (4) and the system of the primary conductor loops to the electrical energy source (3). All primary conductor loops of the charging section (2), and the secondary conductor loop may be implemented as double dipole loops (6,7,8).