Wireless Charging Volume Foreign Object Detection by Q Factor
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Solution Overview
Problem
Current wireless power transfer systems face challenges in efficiently transferring power over longer distances and larger volumes while minimizing electromagnetic interference and heat generation, particularly in multi-device charging applications, where alignment and heat dissipation are critical issues.
Innovation Solution
The system incorporates custom-shaped components with magnetic materials to concentrate magnetic fields, advanced heat dissipation features, and firmware settings to manage heat and optimize power transfer, enabling efficient wireless power transmission at extended distances and volumes with reduced electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If transmitter inductance and receiver inductance are increased to counteract coupling decrease at larger distances, then power transfer capability is improved, but equivalent series resistance increases leading to more heat and greater energy losses
Solution Approach 1:
The patent applies parameter changes by modifying the operating frequency of the wireless power transfer system. By tuning the system to operate at its resonant frequency, the patent achieves enhanced power transfer capability at larger distances without proportionally increasing inductance values. This frequency optimization allows the system to maintain lower equivalent series resistance while achieving the desired power transfer, thereby reducing energy losses and heat generation compared to simply increasing inductance values.
2Power
If transmitter inductance and receiver inductance are increased to counteract coupling decrease at larger distances, then power transfer capability is improved, but heat levels rise excessively causing component damage or shutdown
Solution Approach 1:
The patent utilizes parameter changes by optimizing the operating frequency to match the resonant frequency of the transmitter and receiver coils. This resonant frequency tuning enables effective power transfer over larger distances without requiring excessive inductance increases that would generate prohibitive heat levels. The frequency optimization creates a balanced operating point where power transfer capability is enhanced while thermal management remains within safe component operating limits.
3Power
If transmitter inductance and receiver inductance are increased to counteract coupling decrease at larger distances, then power transfer capability is improved, but electromagnetic interference increases
Solution Approach 1:
The patent applies parameter changes by carefully selecting and optimizing the operating frequency of the wireless power transfer system. By operating at the resonant frequency, the system achieves improved power transfer capability at larger distances while minimizing electromagnetic interference. The resonant frequency optimization creates a more focused and efficient magnetic field coupling, reducing stray electromagnetic fields and interference with other electronic components compared to systems that simply increase inductance values to achieve the same power transfer.
4Reliability
If devices are placed within a charging bay or in contact with the charging bay for charging, then charging effectiveness is achieved, but oversized devices cannot be charged and charging distance is limited
Solution Approach 1:
The patent applies parameter changes by optimizing the operating frequency and adjusting system parameters to enable wireless power transfer over extended distances. This frequency and parameter optimization allows the charging system to accommodate oversized devices that cannot fit within traditional charging bays or make contact with the charging surface. The enhanced frequency-tuned system maintains charging effectiveness while providing the adaptability to charge various device sizes and configurations without requiring physical contact or bay confinement.
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 solution allows for more effective power transfer over longer ranges and larger volumes with reduced heat buildup and electromagnetic interference, enhancing the reliability and efficiency of wireless power systems in demanding applications.
Implementation Method 1
Inductive wireless power transfer occurs when magnetic fields created by a transmitting element induce an electric field, and hence electric current, in a receiving element
Implementation Method 2
a magnetic material positioned behind the transmitter coil, wherein the magnetic material redirects magnetic field flux generated by the transmitter coil
Data Source
AI summary
A wireless power transmission system includes a wireless power transmitter, a wireless power transfer circuit electrically connectable to the at least one wireless power transmitter, and a transmitter controller. The transmitter controller is configured to perform an initial foreign object detection prior to any transmission of wireless power, the initial foreign object detection for detecting presence of a foreign object within a charge volume, the initial foreign object detection determining an initial quality factor (Q). The controller is further configured to begin wireless power transfer negotiations with one of the one or more wireless power receivers, if the initial Q has a value in a range indicating that an object in the charge volume is a wireless power receiver, and perform continuous foreign object detection, if the initial Q has the value in the range indicating that an object in the charge volume is a wireless power receiver.