Wireless Power Transfer Coil Position Detection Using Reference Calibration
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Solution Overview
Problem
Existing wireless power transfer systems face challenges in accurately determining the position of an object within a charge region, affecting power transfer efficiency due to varying signal intensities from multiple coils, which can lead to errors in object detection and positioning.
Innovation Solution
A wireless power transfer apparatus with multiple coils and a controller that calculates data values for each coil, comparing them to preset reference values to accurately determine the object's position and optimize power transfer efficiency by compensating for signal intensity variations and using resonance circuits with capacitors to enhance coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple coils are used to expand the charge region, then the coverage area is improved, but the accuracy of object position determination deteriorates due to signal intensity variations from different coils
Solution Approach 1:
The patent applies local quality by storing different reference values for signal intensity in the memory unit, corresponding to different coil positions and objects. Each coil's signal characteristics are individually calibrated and stored, allowing the system to account for local variations in signal intensity across the charge region. This enables accurate position determination despite using multiple coils with different signal strengths.
Solution Approach 2:
The system changes the parameter of reference signal intensity values based on the specific coil and object being measured. By storing pre-calibrated reference values for each coil-object combination and adjusting the comparison threshold according to the active coil, the system compensates for signal intensity variations. This parameter adaptation allows multiple coils to be used without sacrificing position determination accuracy.
2Device complexity
If signal intensity comparison is used to determine object position, then the detection method is simplified, but the reliability deteriorates due to variations in signal intensity from different coils
Solution Approach 1:
The patent applies preliminary action by pre-calibrating and storing reference signal intensity values in the memory unit before actual operation. The system performs preliminary measurements for each coil and object combination, storing these reference values for later comparison. This advance preparation ensures that during operation, the system can reliably determine object position by comparing current signals against pre-established references, without needing complex real-time adjustments.
3Device complexity
If the primary coil position is fixed, then the system structure is simplified, but the power transfer efficiency deteriorates when the secondary coil position varies
Solution Approach 1:
The patent applies feedback by using the object detection unit to continuously monitor the position of the secondary coil relative to the primary coil. When misalignment is detected, the system provides feedback to guide the user to adjust the secondary coil to the optimal position. This feedback mechanism maintains high power transfer efficiency without requiring complex active positioning systems, as the fixed primary coil structure is preserved while enabling adaptive response to position variations.
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 precise determination of an object's position and improved power transfer efficiency by compensating for signal intensity differences and optimizing coil configurations, reducing errors in object detection and enhancing user guidance for optimal positioning.
Implementation Method 1
As a wireless power supply method, an inductive coupling method is mainly used, and the method uses a principle whereby a magnetic field is changed by current flowing in a primary coil of two adjacent coils when intensity of the current is changed, and thus magnetic flux through a secondary coil is changed and induced electromotive force is generated at the secondary coil
Implementation Method 2
the controller is configured to control the power transmitter to transfer power to the power receiver through the resonance circuit
Data Source
AI summary
Disclosed are a wireless power transfer apparatus and a method of controlling the same. The wireless power transfer apparatus in one example can include a power transmission circuit including a plurality of coils and configured to transfer power through the plurality of coils, and a controller, wherein the controller is configured to calculate a data value of a coil with respect to each of the plurality of coils, and determine a position of an object in a charge region corresponding to the plurality of coils in a charge region based on a comparison result obtained by comparing the data value calculated for each of the plurality of coils.