Wireless Power Transmitter Frequency Tuning in Metallic Environments
Solution Overview
Problem
Magnetic resonance-based wireless power transmission systems face inefficiencies when metals are present, as they alter resonance frequencies, and existing methods to adjust capacitance are limited and do not effectively adapt to metal interference.
Innovation Solution
A power wireless transmitter with a variable drive frequency signal generator, switching unit, and frequency detection unit that adjusts drive frequency and duty ratio to maintain efficient transmission by detecting amplitude changes and feeding back optimal frequencies and duty ratios for maximum output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If capacitance of the wireless power transmitter is adjusted to keep resonance frequency constant, then resonance frequency stability is improved, but the number of times of capacitance changes is limited
Solution Approach 1:
The patent implements dynamic frequency adjustment by introducing a frequency detection unit and controller that continuously monitor and adjust the drive frequency in real-time based on detected resonance frequency changes, replacing the static capacitance adjustment method with a dynamic frequency tuning mechanism that can adapt indefinitely to varying metal interference conditions
Solution Approach 2:
The patent changes the adjustable parameter from capacitance to drive frequency. By detecting resonance frequency shifts caused by metal objects and adjusting the drive frequency to match the new resonance frequency, the system achieves continuous adaptability without the mechanical limitations of capacitor switching
2Productivity
If drive frequency is adjusted to match receiver resonance frequency, then wireless power transmission efficiency is improved, but transmission efficiency deteriorates when metal changes resonance frequency
Solution Approach 1:
The patent implements a feedback mechanism where the frequency detection unit continuously monitors the resonance frequency of the transmitter, and the controller adjusts the drive frequency based on this feedback to maintain alignment with the receiver's resonance frequency even when metal objects cause frequency shifts, ensuring reliable efficient transmission
Solution Approach 2:
The patent performs preliminary frequency detection and adjustment before power transmission begins. The frequency detection unit detects the resonance frequency in advance, and the controller pre-adjusts the drive frequency to match, ensuring efficient transmission from the start even in the presence of metal interference
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 ensures efficient wireless power transmission by dynamically adjusting drive frequency and duty ratio in response to metal presence, maintaining optimal resonance and enhancing transmission efficiency.
Implementation Method 1
a variable drive frequency signal generator configured to receive a drive voltage from the power supply and generate a variable drive frequency signal for wireless power transmission
Implementation Method 2
a switching unit configured to receive the variable drive frequency signal from the variable drive frequency generator and to switch and amplify the variable drive frequency signal
Implementation Method 3
a wireless power transmission unit configured to receive the variable drive frequency signal from the switching unit and to wirelessly transmit a power to a wireless power receiving unit using the variable drive frequency signal
Implementation Method 4
a frequency detection unit configured to detect an amplitude of the variable drive frequency signal outputted from the wireless power transmission unit
Data Source
Figure 1~2
AI summary
The present disclosure is to provide a power wireless transmitter in a magnetic resonance-based wireless power transmission system, wherein when, due to a presence of a metal, an output from the wireless power transmitter has a change in a resonance frequency thereof, a drive frequency and/or duty ratio with a maximum output therefrom are determined to be applied for a transmission from the wireless power transmitter, thereby to achieve an efficient wireless power transmission.