Wireless Power Control for Foreign Object Detection During Charging
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Solution Overview
Problem
Existing wireless charging technologies face challenges in accurately detecting foreign objects, leading to reduced charging efficiency, increased temperatures, and potential damage to charging devices.
Innovation Solution
A method and apparatus for controlling wireless power transmission that includes a first packet reception phase, a determination phase to assess the presence of foreign objects, and a power control phase to adjust transmission power based on the determination, thereby minimizing foreign object detection errors and preventing unnecessary charging stops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wireless power transmission is performed at high power, then charging efficiency is improved, but temperature increases and device damage risk increases
Solution Approach 1:
The patent implements dynamic power adjustment by continuously monitoring foreign object detection results and adapting transmission power levels accordingly. The system transitions between different power transmission modes (first mode with higher power, second mode with reduced power) based on real-time FOD status, optimizing charging efficiency while preventing overheating when foreign objects are detected
Solution Approach 2:
The system employs feedback mechanisms through continuous foreign object detection during power transmission. The detection results feed back to the power control module, which adjusts transmission power in response to detected conditions, creating a closed-loop control system that balances charging efficiency with safety
2Reliability
If foreign object detection sensitivity is increased, then safety is improved, but false detection rate increases leading to unnecessary charging stops
Solution Approach 1:
The patent changes detection parameters dynamically by adjusting detection thresholds and power levels based on operating conditions. The system uses different detection sensitivities in different power transmission modes, and adjusts detection parameters according to the specific charging scenario, thereby reducing false detections while maintaining safety
Solution Approach 2:
The system dynamically adapts detection strategies based on power transmission mode and detected conditions. Rather than using fixed detection thresholds, the system modifies detection parameters in real-time to balance sensitivity with false alarm reduction, improving overall detection reliability
3Reliability
If continuous foreign object detection is performed, then safety is improved, but energy consumption increases
Solution Approach 1:
The patent implements periodic foreign object detection at specific intervals during power transmission rather than continuous monitoring. The system performs FOD checks at designated phases (packet reception phase, determination phase, power control phase) and adjusts detection frequency based on operational context, reducing energy consumption while maintaining safety
Solution Approach 2:
The detection frequency and intensity are dynamically adjusted based on power transmission mode and detected conditions. The system intensifies detection when foreign objects are suspected and reduces detection activity during stable charging periods, optimizing the balance between safety and energy consumption
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 solution effectively enhances the accuracy of foreign object detection, prevents device damage due to overheating, and ensures seamless charging by adaptively controlling transmission power.
Implementation Method 1
wireless power transmission technology refers to technology of wirelessly transmitting electric energy from a transmitter to a receiver using the principle of magnetic induction
Implementation Method 2
a wireless energy transfer method may be roughly divided into a magnetic induction method, an electromagnetic resonant method and a power transmission method using a short-wavelength radio frequency
Implementation Method 3
If a conductor which is not a wireless power receiver—that is, a foreign object (FO)—is present in a wireless charging area, an electromagnetic signal received from a wireless power transmitter may be induced in the FO
Data Source
AI summary
A method of controlling a power transmitter, the method including entering a negation phase with a power receiver including receiving a foreign object detection status packet from the power receiver, detecting whether a foreign object is present based on the foreign object detection status packet, and transmitting a NACK response to the power receiver indicating the power transmitter has detected the foreign object is present or transmitting an ACK response to the power receiver indicating the power transmitter has detected the foreign object is not present; and entering a power transfer phase including transmitting a first power to the power receiver in response to the transmitted NACK response and again detecting whether the foreign object is present while transmitting the first power, and transmitting a second power greater than the first power in response to the transmitted ACK response.