Inductive Power Coil Detector Pairs for Metal Object Detection
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Solution Overview
Problem
Current inductive power transmission systems for electric vehicles lack a cost-effective and reliable method to detect metal objects in the transmission path, as conventional metal detectors interfere with the strong magnetic field and fail to detect small or flat objects, and existing optical and ultrasound systems have limitations.
Innovation Solution
The apparatus uses detector coil pairs wound in opposite directions to measure changes in the magnetic field, leveraging the existing energy transmission field for detection, allowing for the identification of metal objects by analyzing induced voltages, which are compensated in homogeneous fields and increased in inhomogeneous fields, enabling robust and reliable detection of metal objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional metal detectors are used to detect metal objects in the transmission path, then metal objects can be detected, but the detectors interfere with the strong magnetic field and fail to detect small or flat objects
Solution Approach 1:
The patent combines the power transmission function and metal detection function into a single integrated system. The same magnetic field used for inductive power transmission is also utilized for detecting metal objects, eliminating the need for separate detection fields or additional complex detection systems.
Solution Approach 2:
The detector coil pairs serve multiple functions: they detect metal objects by measuring changes in the magnetic field while simultaneously being part of the inductive power transmission system. The existing transmission field serves dual purposes as both power carrier and detection medium.
2Adaptability or versatility
If optical or ultrasound systems are used for detection, then additional detection capabilities are provided, but these systems have limitations and increase system complexity
Solution Approach 1:
The patent merges the power transmission field with the detection function, using the same magnetic field for both purposes. This eliminates the need for separate optical or ultrasound detection systems and their associated complexity.
Solution Approach 2:
The inductive power transmission system performs self-detection of metal objects using its own magnetic field. The system detects objects by measuring changes in its self-generated field, eliminating the need for external or additional detection systems.
3Measurement precision
If detector coil pairs wound in opposite directions are used, then voltages are compensated in homogeneous fields and local inhomogeneities are detected, but the detection system must handle complex voltage compensation
Solution Approach 1:
The detector coil pairs are wound in opposite directions (asymmetric winding), which creates opposite polarity voltages when exposed to magnetic fields. This asymmetric configuration enables automatic compensation of homogeneous field voltages while detecting inhomogeneities caused by metal objects.
Solution Approach 2:
The patent changes the winding direction parameter of the detector coils to achieve voltage compensation. By winding coils in opposite directions, the system transforms the detection mechanism to automatically compensate for homogeneous field effects while maintaining sensitivity to local inhomogeneities.
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 allows for reliable detection of metal objects, including small ones, by utilizing the existing transmission field for excitation, providing comprehensive coverage without additional detection fields, and is sensitive to local inhomogeneities, ensuring safe and efficient energy transfer during charging.
Implementation Method 1
the primary coil generates a magnetic transmission field in a transmission area between the primary unit and the secondary unit
Implementation Method 2
the detector coil elements being wound in opposite directions in pairs and forming a detector pair for detecting an induction voltage
Data Source
AI summary
Apparatus for inductively transmitting power, which apparatus comprises a primary unit with a primary coil and a secondary unit with a secondary coil, and in which the primary coil induces a magnetic transmission field in a transmission area between the primary unit and the secondary unit, and which has an even number of detector coil elements which are wound in opposite directions in pairs and form a detector pair.