Q-Factor Foreign Object Detection for Large-Volume Wireless Charging
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Solution Overview
Problem
Existing wireless power transfer systems face challenges in efficiently transmitting power over longer distances and larger volumes while minimizing electromagnetic interference, heat generation, and maintaining system reliability, particularly in environments with multiple devices and harsh conditions.
Innovation Solution
The system incorporates magnetic field reshaping and focusing components, heat dissipation features, and rugged design elements to enhance power transfer efficiency and reduce interference, using materials like magnetic and ferrimagnetic materials, multi-layer coils, and firmware settings to manage heat and interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If transmitter inductance and/or receiver inductance are increased to counteract coupling decrease at larger distances, then power transfer capability is improved, but equivalent series resistance increases causing more heat and greater energy losses
Solution Approach 1:
The patent changes the operating frequency parameter to achieve better power transfer at larger distances without increasing inductance. By operating at optimized frequencies, the system achieves improved coupling and power transfer capability while avoiding the energy losses associated with higher inductance values.
2Power
If transmitter inductance and/or receiver inductance are increased to counteract coupling decrease at larger distances, then power transfer capability is improved, but heat generation increases
Solution Approach 1:
The patent employs frequency parameter optimization to achieve effective power transfer at extended distances without the need for increased inductance. This approach prevents excessive heat generation while maintaining the required power transfer capability, as the system operates at frequencies that maximize coupling efficiency.
3Power
If inductance is increased to transmit power effectively at larger distances, then coupling is improved, but electromagnetic interference increases
Solution Approach 1:
The patent utilizes frequency optimization to achieve effective power transfer at larger distances without increasing inductance. By selecting appropriate operating frequencies, the system maintains good coupling and power transfer while minimizing electromagnetic interference, thus avoiding the harmful effects associated with high inductance values.
4Adaptability or versatility
If charging distance is extended to accommodate device size and design constraints, then adaptability is improved, but power transfer efficiency decreases
Solution Approach 1:
The patent achieves extended charging distances with maintained efficiency by optimizing the operating frequency parameter. This allows the system to accommodate larger device sizes and design constraints while preventing the efficiency losses that would normally occur at extended distances, as the frequency optimization compensates for the increased separation between transmitter and receiver.
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
Enables effective power transfer at extended distances and volumes with reduced electromagnetic interference and heat buildup, supporting multiple devices and harsh environments without active cooling, and optimizing system performance.
Implementation Method 1
magnetic field reshaping and focusing components
Implementation Method 2
generate a sufficiently high concentration of magnetic field flux
Implementation Method 3
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 4
heat dissipation features
Implementation Method 5
heat levels rise excessively
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.