Wireless Power Coupling Detection for Misalignment and Heat Control
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Solution Overview
Problem
Conventional wireless power transmission systems lack effective methods for controlling power transmission when electromagnetic coupling between the power transmission and reception antennas is weak, which can occur due to misalignment, distance, or the presence of foreign substances, leading to inefficiencies and potential damage from increased heat generation.
Innovation Solution
A power transmission device equipped with a detection unit that performs object detection based on parameters such as distance and electromagnetic coupling, using methods like Q-value measurement and waveform attenuation to adjust power transmission and suppress noise, instability, and improve detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If wireless power transmission is performed when electromagnetic coupling is weak, then power transmission continues without interruption, but heat generation increases and efficiency decreases
Solution Approach 1:
The system performs preliminary detection of electromagnetic coupling strength before initiating full power transmission. By measuring coupling status in advance and comparing it against threshold values, the system determines whether to proceed with power transmission or terminate it to avoid excessive heat generation, thus preventing the harmful effect before it occurs
Solution Approach 2:
The system continuously monitors electromagnetic coupling strength during power transmission and uses this feedback to control transmission operation. When coupling strength falls below a predetermined threshold, the system automatically stops or adjusts power transmission to maintain efficient operation and prevent overheating
2Ease of operation
If electromagnetic coupling between antennas is weak, then misalignment or distance issues occur, but power transmission efficiency decreases
Solution Approach 1:
The system performs preliminary measurement of electromagnetic coupling strength using Q-value or waveform attenuation detection before initiating power transmission. This allows the system to identify misalignment or distance issues in advance and take corrective actions such as adjusting antenna positions or notifying the user, thereby preventing energy loss from inefficient transmission
Solution Approach 2:
The system continuously monitors coupling strength during operation and provides feedback control. When coupling falls below acceptable thresholds indicating misalignment or excessive distance, the system adjusts transmission parameters or stops operation to prevent significant energy loss, maintaining overall transmission efficiency
3Reliability
If object detection is not performed, then foreign substances may be present, but detection accuracy is insufficient with conventional methods
Solution Approach 1:
The system uses electromagnetic coupling strength as an intermediary parameter to detect the presence of foreign substances. By measuring changes in Q-value or waveform attenuation caused by foreign objects between the transmission and reception antennas, the system achieves reliable detection without requiring direct contact or additional sensors, thereby improving both reliability and measurement precision
Solution Approach 2:
The system uses the same electromagnetic field and measurement infrastructure for multiple purposes: power transmission, coupling strength measurement, and foreign substance detection. This multi-functional approach improves detection reliability by using the inherent electromagnetic interactions while avoiding additional complex detection systems
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 power transmission efficiency and safety by accurately detecting foreign substances and misalignments, reducing noise, and maintaining stable communication, thereby preventing overheating and ensuring reliable power transfer.
Implementation Method 1
a power transmission unit configured to wirelessly transmit power to a power reception device via a coil
Implementation Method 2
a detection unit configured to perform an object detection on basis of a parameter according to distance from the coil to an exterior of a housing of the power transmission device
Data Source
AI summary
A power transmission device, which wirelessly transmits power to a power reception device, detects an object by transmitting an analog ping. The power transmission device transmits a digital ping and the power reception device is activated to perform communication. The power transmission device determines the strength of electromagnetic coupling between a power transmission antenna and a power reception antenna using a plurality of analog pings or digital pings having different conditions. When it is recognized that the electromagnetic coupling between the two antennas is weak, the power transmission device performs control for suppressing noise leaking from the antenna to the surroundings, control for suppressing instability in communication between the power transmission device and the power reception device; and control for suppressing deterioration in accuracy of detection of an object located between the power transmission device and the power reception device.