Wireless Power Coil Loss Analysis for Foreign Object Detection
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Solution Overview
Problem
Wireless power transmission systems face inefficiencies due to power loss caused by foreign objects, which current foreign object detection techniques fail to adequately address.
Innovation Solution
A wireless power transmission device equipped with a controller that measures and calculates loss power by analyzing transmission and reception currents, phase differences, and load resistance to identify foreign objects based on a reference value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless power transmission is performed using magnetic induction method, then power can be transmitted wirelessly, but power loss occurs due to foreign objects in the transmission path
Solution Approach 1:
The patent detects foreign objects by measuring the power loss caused by them. The harmful effect of foreign objects (power loss) is converted into a useful detection signal. By monitoring the difference between transmitted power and received power, the system identifies the presence of foreign objects and can take appropriate actions to prevent safety issues.
2Measurement precision
If foreign object detection is performed using conventional techniques, then detection capability is limited, but system complexity increases
Solution Approach 1:
The patent uses the existing power transmission components (transmission coil, controller) to perform both power transmission and foreign object detection functions. The controller calculates loss power by comparing transmitted power with received power, utilizing the same hardware infrastructure for dual purposes, thereby avoiding additional complex detection equipment.
Solution Approach 2:
The system continuously monitors the power transmission process by receiving feedback information from the wireless power reception device about received power levels. This feedback loop enables real-time calculation of loss power and ongoing foreign object detection without requiring separate measurement 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
Effectively identifies and mitigates power loss from foreign objects, enhancing the efficiency of wireless power transmission by accurately detecting and differentiating between intended receivers and foreign objects.
Implementation Method 1
Wireless power transmission technology using a magnetic induction method is a method of transferring power using an electromagnetic field induced in a coil, wherein a wireless power transmission device may generate an electromagnetic field by applying a current to a transmission coil, and an induced electromotive force is formed in a reception coil
Data Source
AI summary
A wireless power transmission device according to an embodiment may include: a transmission coil, at least one controller, comprising processing circuitry and memory storing instructions. At least one controller is configured to cause the wireless power transmission device to: receive first information from a wireless power reception device, wherein the first information may include information related to a transmission current of the transmission coil and mutual loss power; receive second information from the wireless power reception device, wherein the second information may include information related to a reception current of a reception coil of the wireless power reception device, a phase difference between the reception current and the transmission current, and/or a load resistance of the wireless power reception device; measure a first transmission current of the transmission coil; calculate first mutual loss power, based on the first information and the first transmission current; calculate first loss power, based on the first mutual loss power and the second information, wherein the first loss power may include loss power generated by magnetic flux of the transmission coil, magnetic flux of the reception coil, and/or mutual magnetic flux connected between the transmission coil and the reception coil; measure second loss power between the wireless power transmission device and the wireless power reception device; and identify a foreign object, based on a difference between the first loss power and the second loss power being greater than or equal to a reference value.