Wireless Charging Power Control Using Multi-Stage Foreign Object Checks
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Solution Overview
Problem
Existing wireless charging technologies face challenges in accurately detecting foreign objects, leading to inefficient charging, potential overheating, and damage due to incorrect foreign object detection, which results in unnecessary power waste and device damage.
Innovation Solution
A method and apparatus for controlling wireless power transmission that includes multiple determination phases to accurately detect foreign objects by measuring power loss and temperature changes, adjusting transmission power levels, and renegotiating power transfer contracts to prevent damage and ensure seamless charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless power transmission is performed using electromagnetic induction or resonance, then power can be transmitted wirelessly to charging devices, but foreign objects in the charging area may be heated causing safety issues and charging interruptions
Solution Approach 1:
The system performs foreign object detection before initiating full power transmission by measuring impedance characteristics of the charging coil. This preliminary detection identifies foreign objects in advance, preventing them from being heated during charging. The impedance measurement is conducted at a specific frequency to detect changes caused by foreign objects, allowing the system to alert users or prevent charging before harmful heating occurs.
2Reliability
If foreign object detection sensitivity is increased to prevent heating, then safety improves, but false detections increase causing unnecessary charging stops
Solution Approach 1:
The system continuously monitors impedance characteristics during charging and compares real-time measurements with reference values. When impedance changes exceed a threshold, the system provides feedback to adjust detection sensitivity or initiate safety protocols. This feedback mechanism allows dynamic adjustment between detection sensitivity and false alarm reduction, maintaining both safety and charging continuity.
Solution Approach 2:
The system changes detection parameters such as measurement frequency and impedance threshold based on charging conditions. By adjusting these parameters dynamically, the system optimizes detection accuracy for different scenarios, reducing false detections while maintaining sensitivity to actual foreign objects. Parameter changes allow the system to adapt to varying charging environments and minimize unnecessary charging interruptions.
3Speed
If power transmission intensity is increased for faster charging, then charging speed improves, but energy loss increases when foreign objects are present
Solution Approach 1:
The system performs impedance-based foreign object detection before initiating high-power transmission. By detecting foreign objects in advance using coil impedance measurements, the system prevents power waste from heating foreign objects. Only when no foreign objects are detected does the system proceed with high-intensity power transmission for fast charging, ensuring both speed and energy efficiency.
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 enhances foreign object detection accuracy, preventing unnecessary charging stops, reducing power waste, and protecting devices from overheating by dynamically adjusting power transmission based on real-time environmental changes.
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
a first determination phase of determining whether the foreign object is present based on power loss
Implementation Method 3
a second determination phase of determining whether the foreign object is present based on temperature change
Implementation Method 4
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
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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.