Opposing Coil Magnetic Coupling for Foreign Matter Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing contactless power supply systems face challenges in accurately detecting foreign matter, such as metal housings, which can lead to false positives or negatives due to the presence of metal components within the device, affecting the reliability of foreign metal detection methods that rely on changes in electrical parameters.
Innovation Solution
A detecting apparatus using a magnetic coupling system with multiple coils, where the coils are electrically connected to have opposing magnetic flux orientations, allowing for the measurement of electrical parameters like the Q factor to determine the presence of foreign matter without additional sensors, thereby improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If foreign matter detection is performed using changes in electrical parameters in existing contactless power supply systems, then detection capability is provided, but detection accuracy deteriorates due to false positives or negatives caused by metal components within the device
Solution Approach 1:
The detector coil is divided into multiple coils (first coil and second coil) with different magnetic flux orientations. This segmentation allows the system to detect foreign matter by comparing signals from coils with different sensitivities, thereby distinguishing true foreign matter detections from false positives caused by device metal components.
Solution Approach 2:
Different coils are designed with different local qualities in terms of magnetic flux orientation and sensitivity characteristics. The first coil has higher sensitivity to foreign matter in certain regions while the second coil has different sensitivity characteristics, allowing the system to use these local quality differences to improve detection accuracy through signal comparison.
2Measurement precision
If multiple coils with opposing magnetic flux orientations are used in the detector, then detection accuracy is improved by minimizing magnetic flux leakage and noise, but device complexity increases
Solution Approach 1:
Multiple coils with different magnetic flux orientations are merged into a single detector unit. This combining approach allows the system to achieve improved detection accuracy through signal comparison while integrating the functionality into one compact detector structure, thereby limiting the increase in overall device complexity.
Solution Approach 2:
The detector with multiple coils serves multiple functions: it can detect foreign matter with improved accuracy, minimize magnetic flux leakage, and reduce unwanted noise. This multi-functionality justifies the increased complexity by providing several benefits from a single integrated detector design.
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 approach enhances the accuracy of foreign matter detection by minimizing magnetic flux leakage and unwanted noise, allowing for precise identification of foreign materials generating heat due to magnetic flux, even in the presence of metal components within the device.
Implementation Method 1
Electromagnetic induction is established as a technique for supplying power in a contactless manner
Implementation Method 2
there is a risk of causing the foreign matter to generate heat due to the magnetic flux passing through that foreign matter
Implementation Method 3
Such heat generation in foreign matter may lead to currents being produced in a foreign metal due to the magnetic flux passing through the foreign metal (eddy currents, current loops, circular currents)
Implementation Method 4
a magnetic coupling element that magnetically couples with another magnetic coupling element or foreign matter
Data Source
AI summary
There is provided a detecting apparatus including one or a plurality of magnetic coupling elements that include a plurality of coils, and a detector that measures an electrical parameter related to the one or plurality of magnetic coupling elements or to a circuit that at least includes the one or plurality of magnetic coupling elements, and determines from a change in the electrical parameter whether a foreign matter that generates heat due to magnetic flux is present. In the one or plurality of magnetic coupling elements, the plurality of coils are electrically connected such that magnetic flux produced from at least one or more of the plurality of coils and magnetic flux produced from remaining coils of the plurality of coils have approximately opposing orientations.