Wireless Power Supply Frequency Control for Resonance Mismatch

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Solution Overview

Problem

In wireless power supply systems using electromagnetic field resonance, efficiency and reliability of power transmission decrease when the resonance frequency of the power reception apparatus varies, leading to potential failure in supplying power.

Innovation Solution

A wireless power supply system that includes a frequency determination unit to adjust the frequency of AC power supplied to the power transmission element based on measured first and second frequencies, allowing for efficient power transmission even when the frequency range changes, with features like detection of power supply state, frequency measurement, and storage of optimal supply frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the resonance frequency of the power reception apparatus is fixed, then the power supply system operates efficiently at a specific frequency, but the system cannot adapt when the frequency range of AC power capable of being supplied varies

Engineering Contradiction:
Improvepower supply reliabilityVSAvoidfrequency range adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic frequency adjustment by measuring the actual resonance frequency of the power reception apparatus and adjusting the transmission frequency accordingly. The frequency measurement unit continuously monitors the resonance frequency, and the frequency adjustment unit dynamically modifies the AC power frequency supplied to the power transmission element to match the measured resonance frequency, enabling the system to adapt to frequency variations while maintaining efficient power transfer.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the frequency parameter of the AC power supplied to the power transmission element based on measured resonance frequency. By adjusting this critical parameter, the system maintains optimal power transfer efficiency across varying operating conditions and frequency ranges, resolving the contradiction between fixed-frequency efficiency and frequency adaptability.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If continuous frequency measurement is performed to maintain optimal power transfer, then power supply efficiency is maximized, but system complexity and measurement requirements increase

Engineering Contradiction:
Improvepower transfer efficiencyVSAvoidfrequency measurement and control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The power reception apparatus performs self-measurement of its resonance frequency and transmits this information to the power transmission apparatus. This self-service approach eliminates the need for complex continuous measurement systems on the transmission side, reducing overall system complexity while maintaining optimal power transfer efficiency through accurate frequency matching.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs frequency measurement and adjustment in advance before power supply begins, and stores the measured resonance frequency for subsequent power transfer operations. This preliminary action eliminates the need for continuous measurement during power supply, reducing system complexity and measurement requirements while maintaining high power transfer efficiency.

Inventive Principle:
Principle #10Preliminary action

3Loss of energy

If the frequency of AC power is adjusted to match varying resonance frequencies, then power supply efficiency is maintained, but the system requires additional control mechanisms

Engineering Contradiction:
Improvepower supply efficiencyVSAvoidfrequency control mechanism complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the power reception apparatus measures its resonance frequency and transmits this information back to the power transmission apparatus. The transmission apparatus uses this feedback to adjust the AC power frequency, creating a closed-loop control system that maintains optimal power transfer efficiency with minimal complexity through information-based control rather than complex mechanical adjustment mechanisms.

Inventive Principle:
Principle #23Feedback

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

Ensures efficient and reliable power supply to the power reception apparatus by adjusting the frequency of AC power, maximizing power transmission efficiency and allowing for quick recalibration and memory-based power supply without requiring continuous frequency measurement.

Implementation Method 1

power is supplied to the power reception apparatus by using resonance of the electromagnetic field between a power transmission element and a power reception element

Methodology Applied
Scientific EffectElectromagnetic resonance: Resonance

Implementation Method 2

the power transmission element and the power reception element resonate and are electromagnetically coupled to each other

Methodology Applied
Scientific EffectElectromagnetic coupling: Electromagnetic Induction

Data Source

PatentEP2800242B1Wireless power supply system
Publication Date: 2018.08.29 FUJI CORP
  • EP2800242B1 patent drawingFigure 1
  • EP2800242B1 patent drawingFigure 2
  • EP2800242B1 patent drawingFigure 3

AI summary

Provided is a wireless power supply system that supplies AC power to a power reception apparatus by using resonance of an electromagnetic field between a power transmission element and a power reception element. The wireless power supply system includes a changing circuit that changes a frequency of AC power supplied to the power transmission element, and a control device including (A) a frequency changing unit that adjusts the changing circuit to change the frequency of AC power supplied to the power transmission element in a manner capable of being controlled, (B) a frequency measurement unit that measures a first frequency and a second frequency when a state of power supply to the power reception apparatus varies between a state in which AC power is actually supplied and a state in which AC power is not supplied in accordance with the changing of the frequency of AC power, and (C) a frequency determination unit that determines the frequency of AC power during supply of AC power to the power reception apparatus to a frequency between the first frequency and the second frequency. According to this, the frequency of AC power during power supply can be appropriately adjusted, and thus it is possible to efficiently supply power to the power reception apparatus.