Noncontact Power Transmission Foreign Matter Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing noncontact power transmission systems face challenges in accurately detecting metallic foreign matters due to the influence of metallic casings, which complicates the differentiation between casing effects and foreign matter presence, leading to reduced detection accuracy.
Innovation Solution
A detecting system that measures the Q-value of a resonant circuit on the power receiving side using a reading coil to distinguish changes in magnetic flux, allowing for high-accuracy detection of metallic foreign matters without requiring additional hardware or software on the power receiving device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor-based detection method is used to detect metallic foreign matter, then detection capability is provided, but cost increases and design limitations are imposed
Solution Approach 1:
The system uses the existing resonant circuit components (coil and capacitor) to detect metallic foreign matter by measuring changes in their resonant frequency and Q-value. The resonant circuit itself serves the dual purpose of power reception and foreign matter detection, eliminating the need for separate sensor hardware.
Solution Approach 2:
The patent introduces frequency and Q-value measurements as intermediary parameters to indirectly detect the presence of metallic foreign matter. Instead of directly sensing the metal, the system measures how the metal affects the resonant characteristics of the existing circuit components.
2Device complexity
If parameter change methods are used to detect metallic foreign matter, then cost is reduced, but detection accuracy deteriorates due to inability to distinguish casing effects from foreign matter
Solution Approach 1:
The patent transitions from single-parameter detection (e.g., only frequency or only power) to two-dimensional detection by simultaneously measuring both resonant frequency and Q-value. This additional measurement dimension enables differentiation between casing effects and actual foreign matter presence.
Solution Approach 2:
The system continuously monitors the resonant frequency and Q-value of the receiving circuit and compares these measurements against reference values. By analyzing the feedback from these measurements, the system can determine whether changes are due to casing effects or foreign matter intrusion.
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
The system effectively differentiates between metallic casing effects and foreign matter presence, enhancing detection accuracy and eliminating the need for additional hardware or software on the power receiving device, thus improving the reliability of metallic foreign matter detection in noncontact power transmission systems.
Implementation Method 1
a detecting coil for detecting a magnetic field of an electromagnetic wave output from an exciting coil according to the magnetic field
Implementation Method 2
a reading coil for reading a magnetic flux generated by the detecting coil according to the magnetic field
Implementation Method 3
The magnetic field resonance system has a feature of using a resonance phenomenon actively and thereby requiring only a small magnetic flux shared between a feeding source and a feeding destination
Data Source
AI summary
A detecting device includes a reading coil configured to read a magnetic flux generated by a detecting coil for detecting a magnetic field of an electromagnetic wave output from an exciting coil according to the magnetic field. The detecting device further includes a Q-value measuring section configured to measure a Q-value of the detecting coil on a basis of a temporal transition of oscillation of a voltage obtained in the reading coil according to the magnetic flux generated by the detecting coil.