Wireless Power Feeding Coil Position Mismatch Estimation
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Solution Overview
Problem
The existing wireless power transmission systems require a distance sensor to adjust impedance, leading to increased equipment costs and reduced power transmission efficiency due to positional mismatches between resonant coils.
Innovation Solution
A wireless power feeding apparatus that estimates positional mismatch using detected power receiving states and reflected power, eliminating the need for a distance sensor by adjusting impedance based on pre-established relations between these parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a distance sensor is used to measure the distance between primary-side resonant coil and secondary-side resonant coil, then impedance can be adjusted to maintain power transmission efficiency, but equipment cost increases
Solution Approach 1:
The system uses itself to measure distance by utilizing the reflected power characteristics of the resonant system. The primary-side resonant coil and secondary-side resonant coil form a resonant circuit whose reflected power varies with distance, eliminating the need for external distance sensors while maintaining the ability to adjust impedance for optimal power transmission efficiency
Solution Approach 2:
The system implements feedback control by continuously monitoring the reflected power from the resonant system and using this information to determine distance and adjust impedance accordingly. The control unit receives reflected power information, determines distance based on reflected power characteristics, and adjusts the impedance of the resonant system to maintain optimal power transmission efficiency
2Device complexity
If impedance is not adjusted based on distance, then equipment cost is reduced, but power transmission efficiency decreases due to positional mismatch
Solution Approach 1:
The system dynamically changes the impedance parameter of the resonant system based on the distance between primary-side and secondary-side resonant coils. By adjusting impedance according to distance (determined through reflected power characteristics), the system maintains optimal power transmission efficiency without requiring complex additional equipment
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 power transmission efficiency by eliminating the need for a distance sensor, reducing equipment costs and maintaining efficient power transfer across varying distances between power transmission and reception units.
Implementation Method 1
transmits the power in a contactless manner to the power reception unit by resonating with the power reception unit through an electromagnetic field
Implementation Method 2
transmits the power in a contactless manner to the power reception unit by resonating with the power reception unit through an electromagnetic field
Implementation Method 3
The detection device detects reflected power to the power supply device
Data Source
AI summary
A power supply device generates power having a prescribed frequency. A primary self-resonant coil transmits the power in a contactless manner to a secondary self-resonant coil by resonating with the secondary self-resonant coil through an electromagnetic field. A power sensor detects reflected power to the power supply device. A communication device receives a power receiving state of a vehicle. An ECU estimates a positional mismatch amount of the secondary self-resonant coil relative to the primary self-resonant coil based on the power receiving state of the vehicle and the reflected power, by using relation obtained in advance between the power receiving state and the reflected power, and the positional mismatch amount.