Wireless Power Transfer Phasing for Accurate Foreign Object Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless charging technologies face challenges in accurately detecting foreign objects, leading to inefficient charging, potential device damage, and unnecessary power waste due to overheating.
Innovation Solution
A method for controlling wireless power transmission that includes multiple determination phases to detect foreign objects based on power loss and temperature changes, adjusting transmission power levels accordingly to prevent damage and ensure seamless charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wireless power transmission is performed at high power, then charging efficiency is improved, but foreign object detection accuracy deteriorates due to electromagnetic interference
Solution Approach 1:
The power transmission process is segmented into multiple phases: a first power transmission phase at reduced power for foreign object detection, and a second power transmission phase at normal/high power for charging. This temporal segmentation allows accurate detection during the first phase before switching to efficient charging in the second phase.
Solution Approach 2:
Foreign object detection is performed as a preliminary action before initiating high-power charging. The system first transmits at reduced power to detect foreign objects, and only after confirming safety does it proceed to high-power transmission, ensuring detection accuracy is not compromised by electromagnetic interference from high power.
2Reliability
If foreign object detection sensitivity is increased, then safety is improved, but false detection rate increases leading to unnecessary charging interruption
Solution Approach 1:
The system changes the power parameter dynamically based on detection needs. During foreign object detection, power is reduced to a specific level that enables accurate detection without causing false positives. This parameter adjustment allows the system to maintain high detection sensitivity while minimizing false alarms that would interrupt charging.
3Speed
If power transmission is continuously performed without interruption, then charging speed is improved, but device overheating risk increases
Solution Approach 1:
The system implements periodic foreign object detection during power transmission. Instead of continuous uninterrupted transmission, the system periodically interrupts power transmission to perform detection phases, creating a cyclic pattern of transmission-detection-transmission that prevents overheating while maintaining overall charging speed.
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
Enhances foreign object detection accuracy, prevents device damage, and ensures seamless charging by adaptively controlling power transmission based on the presence of foreign objects.
Implementation Method 1
wireless power transmission or wireless energy transfer technology refers to technology of wirelessly transmitting electric energy from a transmitter to a receiver using the principle of magnetic induction
Implementation Method 2
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
Figure 1~2
Figure 3~4
Figure 5
AI summary
Disclosed are a method of controlling wireless power transmission and an apparatus therefor. A method of controlling wireless power transmission of a wireless power transmitter includes a first packet reception phase of receiving a foreign object detection status packet, a first determination phase of determining whether the foreign object is present based on the foreign object detection status packet, and a power control phase of controlling power based on a determination result of the first determination phase, wherein the power control phase includes a first power transfer mode for transmitting first power upon determining that the foreign object is present as the determination result of the first determination phase, and a second power transfer mode for transmitting second power upon determining that the foreign object is not present as the determination result of the first determination phase.