Wireless Power Coil Frequency Shift Control for Variable Coupling

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Solution Overview

Problem

Existing wireless power transfer technologies face challenges in achieving reliable and flexible operation, particularly in determining optimal operating parameters for efficient energy transfer to electrical consumers using inductive coupling, which is affected by magnetic coupling effects and varying design parameters of the receiver.

Innovation Solution

The method involves determining characteristic frequencies of the oscillating circuit under different conditions, including without and with the electrical consumer, and using these frequencies to calculate an operating frequency and duty cycle for the pulse-width-modulated control signal, taking into account the receiver's design parameters and impedance, to optimize power transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the operating frequency is fixed without considering receiver coupling effects, then the apparatus structure is simple, but the power transfer efficiency deteriorates due to magnetic coupling effects and varying receiver characteristics

Engineering Contradiction:
Improveapparatus structure simplicityVSAvoidpower transfer efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the operating frequency adjustable rather than fixed. The control unit dynamically adapts the operating frequency of the transmitter coil based on detected receiver characteristics and coupling conditions, optimizing power transfer efficiency for different scenarios while maintaining system simplicity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating frequency parameter based on detected receiver characteristics. By measuring the impedance or resonant frequency of the receiver and adjusting the transmitter frequency accordingly, the system optimizes power transfer without requiring complex structural modifications

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the operating frequency is adjusted to optimize power transfer, then the power transfer efficiency is improved, but the device complexity increases due to additional control and measurement components

Engineering Contradiction:
Improvepower transfer efficiencyVSAvoidcontrol system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements feedback by detecting receiver characteristics (impedance or resonant frequency) and using this information to adjust the operating frequency. The control unit continuously monitors coupling conditions and adapts the frequency to maintain optimal power transfer, creating a closed-loop control system

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment by automatically detecting receiver characteristics and tuning its own operating frequency without external intervention. The control unit autonomously optimizes power transfer parameters based on real-time coupling conditions

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If the operating frequency is adapted based on receiver characteristics, then the adaptability is improved, but the measurement and control difficulty increases

Engineering Contradiction:
Improveoperating frequency adaptabilityVSAvoidreceiver characteristic measurement
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent performs preliminary measurement of receiver characteristics (impedance or resonant frequency) before initiating full power transfer. This preliminary action allows the system to pre-adjust the operating frequency to optimal values, simplifying subsequent control operations

Inventive Principle:
Principle #10Preliminary 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 allows for efficient and flexible power transfer by compensating for magnetic coupling effects and varying receiver characteristics, ensuring reliable operation and fast settling to desired power levels, even with the presence of ferrites, which enhances the effective coupling between transmitter and receiver coils.

Implementation Method 1

apparatus for wirelessly transmitting electrical power in the direction of an electrical consumer by means of inductive coupling

Methodology Applied
Scientific EffectInductive coupling: Electromagnetic Induction

Implementation Method 2

determining a first characteristic frequency f0_1 of an oscillating circuit comprising the transmitter coil

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4443700A1Method of operating an apparatus for wirelessly transmitting electrical power in the direction of an electrical consumer and system
Publication Date: 2024.10.09 E G O ELEKTRO GERAETEBAU GMBH
  • EP4443700A1 patent drawingFigure 1
  • EP4443700A1 patent drawingFigure 2A~2B
  • EP4443700A1 patent drawingFigure 3

AI summary

Method of operating an apparatus (100) for wirelessly transmitting electrical power in the direction of an electrical consumer (200) by means of inductive coupling, wherein the apparatus (100) comprises: - a rectifier (108) for generating a DC Voltage (Us) based on an alternating mains voltage, - an inverter (102) being supplied by the DC voltage (Us), the inverter (102) being adapted to generate a pulse width modulated control signal (As), and - a transmitter coil (101) being supplied with the pulse width modulated control signal, wherein the transmitter coil (101) is adapted to generate an alternating magnetic field being used to wirelessly transmit the electrical power in the direction of the electrical consumer (200), the method comprising the steps: - determining a first characteristic frequency f0_1 of an oscillating circuit (103) comprising the transmitter coil (101), while the electrical consumer (200) is not inductively coupled to the transmitter coil (101), - determining a second characteristic frequency f0_2 of the oscillating circuit (103) comprising the transmitter coil (101), while the electrical consumer (200) is inductively coupled to the transmitter coil (101) and an electrical load (204) of the electrical consumer (200) is deactivated, and - operating the apparatus (100) depending on a frequency difference Δfc = f0_1 - f0_2.