Wireless Power Transmitter Coupling Estimation From Resonance Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless power transfer systems face inefficiencies and reliability issues due to dependence on precise alignment and coupling factors between transmitter and receiver coils, which can lead to suboptimal performance and delayed adaptation to changing operating conditions.
Innovation Solution
A power transmitter system that includes an output resonance circuit with a transmitter coil and capacitor, a driver for generating a drive signal, a resonance detector to determine coupled resonance frequencies, an estimation circuit to calculate the coupling factor, and an adapter to set operating parameters based on the coupling factor estimate, allowing for improved initial performance, faster adaptation, and enhanced reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the transmitter coil and receiver coil are positioned closer together to improve coupling factor, then power transfer efficiency is improved, but device complexity and ease of operation deteriorate due to severe positioning constraints
Solution Approach 1:
The system dynamically adjusts the drive signal frequency based on detected resonance conditions. The power transmitter continuously monitors the resonance frequency of the output resonance circuit and adapts the operating frequency to maintain optimal coupling, allowing the system to compensate for positioning variations without mechanical constraints
Solution Approach 2:
The invention changes the operating parameter (frequency) of the power transmitter to optimize power transfer. By detecting resonance frequency shifts and adjusting the drive signal frequency accordingly, the system maintains efficient power transfer across different coil positions and coupling conditions
2Loss of energy
If the transmitter and receiver are tightly coupled to improve power transfer, then efficiency is improved, but adaptability to different operating conditions deteriorates
Solution Approach 1:
The system employs feedback by detecting the resonance frequency of the output resonance circuit during operation. The detected resonance information is fed back to the frequency adjustment mechanism, which modifies the drive signal frequency to maintain optimal power transfer under varying operating conditions, loads, and coupling factors
Solution Approach 2:
The power transmitter dynamically adapts its operating frequency based on real-time resonance detection. This dynamic adjustment allows the system to maintain efficient power transfer whether the coupling is tight or loose, and whether the load conditions are light or heavy
3Measurement precision
If a dedicated detection resonance circuit is added to detect coupling conditions, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The output resonance circuit serves multiple functions: it transfers power to the load and simultaneously acts as the detection circuit for resonance frequency measurement. By making the resonance circuit universal, the system achieves accurate coupling detection without adding separate dedicated detection hardware
Solution Approach 2:
The power transmitter's own output resonance circuit provides the detection function. The system uses its inherent resonant properties to detect coupling conditions and resonance frequency shifts, eliminating the need for external or separate detection mechanisms
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
The proposed solution enables improved power transfer efficiency, faster adaptation to optimal operating points, and enhanced reliability by accurately determining coupling factors and adjusting operating parameters, while maintaining low complexity and cost-effectiveness.
Implementation Method 1
power is inductively transferred from a transmitter inductor in a power transmitter device to a receiver coil in the individual devices
Implementation Method 2
a resonance detector arranged to determine a first coupled resonance frequency for the output resonance circuit during a resonance measurement time interval
Data Source
AI summary
A power transmitter (101) comprises a driver (201) generating a drive signal for an output resonance circuit comprising transmitter coil (103) generating a power transfer signal. A resonance detector (307) determines a coupled resonance frequency for the output resonance circuit during where the coupled resonance frequency is a resonance frequency for the output resonance circuit for the transmitter coil (103) being coupled to a receiver coil (107) which is part of a power transfer input resonance circuit of the power receiver (105). The input resonance circuit has a quality factor of no less than ten. An estimation circuit (309) determines a coupling factor estimate for the coupling between the transmitter coil (103) and the receiver coil (107) in response to a non-coupled resonance frequency of the output resonance circuit and the first effective resonance frequency. An adapter (311) sets an operating parameter in response to the coupling factor estimate.