Compensating Coil for Out-of-Phase Field Mitigation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Wireless power transfer systems face challenges in efficiently and safely charging large power receiving units due to out-of-phase magnetic fields at the perimeter of power transmitting coils, leading to voltage stress and design complexities.

Innovation Solution

The implementation of a compensating coil or shielding portion surrounding the perimeter of the power transmitting coil to reduce or eliminate the out-of-phase effect, either by generating a secondary field that opposes the out-of-phase component or by using a metal or ferrite material to shield the receiving unit from this effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a power transmitting coil generates a magnetic field for wireless power transfer, then power transfer capability is improved, but out-of-phase magnetic fields at the perimeter cause voltage stress and design complexities

Engineering Contradiction:
Improvewireless power transfer capabilityVSAvoidvoltage stress on receiving unit
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

A compensating coil is introduced as an intermediary element between the power transmitting coil and the receiving unit. This compensating coil generates a counter-phase magnetic field that cancels out the out-of-phase portion of the original magnetic field, thereby eliminating voltage stress on the receiving unit while preserving the useful power transfer function

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The out-of-phase magnetic field, which originally caused harmful voltage stress, is converted into a beneficial effect by using it to induce current in the compensating coil. This induced current generates a counter-phase field that actively cancels the harmful portion, transforming the problem into a solution mechanism

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

2Power

If a power transmitting coil generates a magnetic field for wireless power transfer, then power transfer capability is improved, but design complexity of receiving units increases

Engineering Contradiction:
Improvewireless power transfer capabilityVSAvoiddesign complexity of receiving unit
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The compensating coil acts as a mediator that pre-processing the magnetic field before it reaches the receiving unit. By canceling the out-of-phase portion upstream, the receiving unit is exposed only to the in-phase, useful magnetic field components, thereby simplifying its design requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful out-of-phase magnetic field effects are counteracted in advance by the compensating coil before the field interacts with the receiving unit. This preliminary cancellation eliminates the need for the receiving unit to have complex protection or compensation mechanisms

Inventive Principle:
Principle #9Preliminary anti-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 approach mitigates voltage stress on the receiving unit, reduces the range of induced voltage, and simplifies the design of power receiving units, allowing for more efficient and reliable wireless power transfer.

Implementation Method 1

a power transmitting coil configured to generate an alternating magnetic field for charging or powering a power receiving unit

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a compensating coil configured to reduce an out-of-phase effect of the alternating magnetic field at a perimeter of the power transmitting coil

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3292635B1Methods and apparatus for out of phase field mitigation
Publication Date: 2021.08.25 QUALCOMM INC
  • EP3292635B1 patent drawingFigure 1~3
  • EP3292635B1 patent drawingFigure 4
  • EP3292635B1 patent drawingFigure 5

AI summary

This invention describes a method and apparatus for providing wireless power. The methods and systems disclosed consist of a first coil having at least one loop forming an inner area inside boundaries of the at least one loop and an outer area outside the boundaries of the at least one loop, the first coil configured to generate a first alternating magnetic field for charging or powering a wireless power device, the first alternating magnetic field having a first magnetic field component with a first phase in the inner area, the first alternating magnetic field also having a second magnetic field component with a second phase in the outer area, and the second phase different from the first phase. In some aspects, the methods and systems comprise a second coil comprising a portion within the outer area, the second coil configured to reduce a magnitude of the second magnetic field component.