Resonator Foreign Object Detection During Wireless Power Transfer
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Solution Overview
Problem
Wireless power transmission efficiency is reduced or the device is damaged due to the presence of foreign materials during operation.
Innovation Solution
A wireless power transmission device with a resonator and inverters configured to detect and identify external objects by applying different frequencies to slots on the resonator, allowing for the detection of foreign materials and controlling power transmission accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If wireless power transmission is performed using a resonator, then power transmission capability is improved, but foreign objects may be heated causing safety issues and efficiency reduction
Solution Approach 1:
The patent performs foreign object detection before initiating full power transmission by applying a detection signal at a different frequency. This preliminary action identifies the presence of foreign objects in advance, allowing the system to prevent harmful heating before it occurs while maintaining the ability to transmit power when safe
Solution Approach 2:
The patent uses an intermediary detection signal at a frequency different from the power transmission frequency to probe for foreign objects. This intermediary signal allows the system to detect foreign objects without directly exposing them to high-power transmission, thus preventing heating while enabling detection
2Productivity
If continuous power transmission is performed, then productivity is improved, but device damage may occur due to foreign objects
Solution Approach 1:
The patent maintains continuous monitoring during power transmission by periodically injecting detection signals at the monitoring frequency. This allows uninterrupted power delivery while continuously detecting foreign objects, ensuring both productivity and safety through ongoing surveillance without interrupting the useful power transmission action
Solution Approach 2:
The patent implements a feedback mechanism where impedance changes detected during power transmission are continuously monitored. When foreign objects are detected through impedance variation, the system provides feedback to adjust or stop power transmission, preventing device damage while maintaining continuous operation when safe
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
Prevents reduction in wireless power transmission efficiency and protects the device from damage by detecting and stopping power transmission to non-target objects.
Implementation Method 1
A wireless power transmission technology corresponds to a scheme of transmitting power by using an electromagnetic field induced on a coil. Through this technology, a current is applied to a transmission coil to generate an electromagnetic field
Implementation Method 2
When a foreign material exists at the time of wireless power transmission device, wireless power transmission efficiency by the wireless power transmission device may be reduced due to the foreign material
Data Source
AI summary
An electronic device is provided. The electronic device includes a resonator in which a first slot is formed, a first inverter connected to a first point and a second point on the first slot of the resonator and configured to provide power to the first slot for detecting a foreign material, the first point and the second point on the first slot being located opposite to each other with the first slot therebetween, a second inverter connected to a third point and a fourth point of the resonator different from the first point and the second point and configured to transfer power to the resonator, and a controller configured to control the first inverter to apply the first power having the first frequency to the first slot, identify at least one first impedance of the first point and the second point while the first power is applied to the first slot, identify, based on the at least one first impedance, an external object adjacent to the electronic device, and control the second inverter to apply a second power having a second frequency different from the first frequency to the third point and the fourth point so as to wirelessly provide power to an external wireless power reception device for a period at least partially overlapping with a period for which the first power is applied to the resonator.