Wireless Charging Power Control with Packet-Based FOD Feedback
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Solution Overview
Problem
Current wireless charging technologies face challenges in accurately detecting foreign objects, leading to inefficient power transmission and potential device damage due to overheating, as they often incorrectly determine the presence of foreign objects, resulting in unnecessary charging stops or continued charging with reduced efficiency.
Innovation Solution
A method and apparatus for controlling wireless power transmission that includes a foreign object detection system using packets to determine the presence of foreign objects based on power loss and temperature changes, allowing for adaptive power control between first and second power transfer modes to prevent damage and ensure seamless charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If foreign object detection is performed using electromagnetic signals, then foreign objects can be detected in the charging area, but detection accuracy is insufficient leading to false positives or negatives
Solution Approach 1:
The patent segments the detection process into multiple independent phases: initial quality factor measurement phase, power transmission phase with power loss detection, and temperature monitoring phase. Each phase uses different detection methods and criteria, allowing the system to cross-validate results and reduce false positives while maintaining high detection accuracy
Solution Approach 2:
The system implements continuous feedback loops where quality factor measurements, power loss data, and temperature readings are constantly monitored and fed back to the controller. This feedback mechanism allows real-time adjustment of detection thresholds and charging parameters, improving both detection accuracy and charging stability through adaptive control
2Productivity
If wireless power transmission continues without accurate foreign object detection, then charging efficiency is maintained, but device damage may occur due to overheating
Solution Approach 1:
The patent performs preliminary quality factor measurements and foreign object detection before initiating full power transmission. This preliminary action identifies potential foreign objects in advance, allowing the system to adjust power levels or prevent charging before overheating can occur, thus protecting devices while maintaining efficient charging when safe
Solution Approach 2:
The system converts the presence of foreign objects, which would normally cause harmful overheating, into a detectable signal. By monitoring quality factor changes, power loss, and temperature variations caused by foreign objects, the system identifies their presence and adjusts operation accordingly, turning a potentially harmful situation into a useful detection opportunity
3Reliability
If foreign objects are detected and charging is stopped immediately, then device safety is protected, but unnecessary charging stops occur due to false detection
Solution Approach 1:
The patent implements dynamic decision-making where the charging control is not static but adapts based on multiple changing parameters. Instead of immediately stopping charging upon any single detection indicator, the system dynamically evaluates combinations of quality factor, power loss, and temperature data over time, adjusting the response based on the severity and consistency of detected anomalies to reduce false stops while maintaining safety
Solution Approach 2:
The system applies beforehand cushioning by implementing gradual power reduction and extended monitoring periods when foreign objects are detected, rather than immediate abrupt shutdowns. This cushioning approach allows time to verify detection accuracy and provides a buffer against false positives, reducing unnecessary charging interruptions while still protecting device safety
4Measurement precision
If multiple detection methods are used to improve accuracy, then detection reliability increases, but system complexity increases
Solution Approach 1:
The patent makes the existing wireless power transmission components perform multiple functions: the transmission coils serve both for power transfer and quality factor measurement, the power management system monitors both power delivery and power loss for foreign object detection, and temperature sensors serve both thermal management and foreign object detection purposes. This multi-functionality reduces the need for separate dedicated detection hardware, lowering system complexity while maintaining high detection accuracy through multiple measurement methods
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 enhances the accuracy of foreign object detection, preventing device damage and ensuring seamless charging by adaptively adjusting power transmission based on the presence of foreign objects, thereby stabilizing wireless power transmission across various environments and receiver types.
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
Implementation Method 3
the temperatures of the wireless power receiver and the wireless power transmitter may increase due to increase in ambient temperature of the FO
Data Source
AI summary
A method of transmitting power of a wireless power transmitter, including a reception phase of receiving a signal including an FOD status packet from a wireless power receiver; a first determination phase of determining whether a foreign object is present in a charging area of the wireless power transmitter based on the FOD status packet; a power control phase of controlling power transmission in a first power transfer mode if it is determined in the first determination phase that the foreign object is present in the charging area, or controlling power transmission in a second power transfer mode if it is determined in the first determination phase that the foreign object is not present in the charging area; a phase of receiving a reception power packet including information on a reception power intensity from the wireless power receiver; a phase of determining the reception power intensity of the wireless power receiver based on information on the reception power intensity; a phase of measuring or calculating a power loss based on a difference between the determined reception power intensity and the transmission power intensity of the wireless power transmitter; a phase of correcting any one of a transmission power, a reception power, and a loss of power using the power loss; and a second determination phase of determining whether the foreign object is present in the charging area while controlling power transmission in the second power transfer mode by the power control phase.