Coil Unit Resonator Segmentation for Foreign Matter Detection Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing contactless power transmission systems face accuracy issues in detecting foreign matter due to multiple resonance frequencies and decreased Q values when using multiple detecting coils without gaps, leading to reduced measuring accuracy.
Innovation Solution
A coil unit with resonators disposed in rows and columns, where each resonator is excited by an excitation coil and has unique distances from the coil, preventing overlap and mutual influence, thereby avoiding multiple resonance frequencies and maintaining high Q values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple detecting coils are disposed without gaps to eliminate dead areas, then the detection coverage is improved, but multiple resonance frequencies are generated and Q values are lowered, deteriorating measurement accuracy
Solution Approach 1:
The patent divides the detection system into multiple independent resonators (first resonator and second resonator) with different resonance frequencies. Each resonator is independently excited and measures, allowing the system to maintain high Q values while covering a broader detection area without the negative effects of mutual interference that would occur with coupled coils.
Solution Approach 2:
The patent introduces frequency dimensionality by using resonators with different resonance frequencies (first resonance frequency and second resonance frequency) instead of spatial arrangement alone. This allows multiple detection points to operate simultaneously without interference, effectively adding a frequency layer to the spatial detection network.
2Ease of operation
If multiple detecting coils are connected to the same capacitor for resonance, then the detection network is completed, but the Q value of each coil is significantly lowered and measuring accuracy becomes worse
Solution Approach 1:
The patent assigns separate capacitors to each resonator (first capacitor for first resonator, second capacitor for second resonator), creating independent resonance circuits. This segmentation prevents the Q value degradation that occurs when multiple coils share a common capacitor, as each resonator maintains its own optimized resonance characteristics.
Solution Approach 2:
Each resonator-c capacitor pair is designed with locally optimized parameters tailored to its specific resonance frequency and detection requirements. This allows each local resonance circuit to operate at peak efficiency with high Q value, rather than compromising overall performance to accommodate multiple coils in a single shared circuit.
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 configuration enhances the accuracy of foreign matter detection during contactless power transmission by preventing resonance frequency interference and maintaining high Q values, improving detection precision.
Implementation Method 1
an excitation coil which excites the plurality of resonators
Implementation Method 2
a plurality of resonators having a resonance coil and a resonance capacitor
Implementation Method 3
resonators having a resonance coil and a resonance capacitor
Implementation Method 4
when the foreign matter is a metal, an eddy current will generate due to the magnetic flux passing through the foreign metal
Implementation Method 5
an eddy current will generate due to the magnetic flux passing through the foreign metal
Implementation Method 6
If the foreign matter is a magnetic body, there will be a hysteresis loss due to the magnetic flux passing through the foreign magnetic body, so that the foreign matter may be heated
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention aims to provide a coil unit for improving an accuracy in detecting foreign matter and an apparatus for detecting foreign matter which improves the accuracy in detecting foreign matter when a power is transmitted in a contactless manner. A power feeding coil unit L100 (a coil unit) of the present invention is provided with a power feeding coil L1 (a coil for power transmission) and an apparatus D100 for detecting foreign matter. The apparatus D100 for detecting foreign matter is provided with a plurality of resonators R1 having a resonator coil M1 and a resonator capacitor C1 and also an excitation coil E1 for exciting the plurality of resonators R1. The plurality of resonators R1 are disposed to cover at least an area interlinking with a magnetic flux generated by the power feeding coil L1 and to decrease an influence of mutual inductance.