Wireless Power Coil Position Estimation Without Added Detection Coils
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Solution Overview
Problem
The existing wireless power feeding systems using magnetic field resonance coupling face challenges in maintaining accurate positional relationships between power transmission and reception devices without compromising the mobility of moving bodies, often resulting in increased weight and size of the power reception device, and potential interference between coils.
Innovation Solution
A wireless power feeding system that employs multiple power transmission devices with coils and a position estimation device to determine the optimal power transmission by analyzing the strength of AC signals received from a power reception coil, allowing for efficient and accurate power transmission and reception without increasing the weight or size of the moving body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a coil L3 is added to the power reception device 200 for position detection, then the position detection capability is improved, but the weight and size of the device increase
Solution Approach 1:
The power reception coil L2 is made to serve dual purposes: both receiving power from the power transmission coil and detecting the position of the power reception device. By utilizing the same coil for both power reception and position detection functions, the patent eliminates the need for a separate detection coil L3, thereby avoiding the increase in weight and size while maintaining position detection capability
Solution Approach 2:
The power reception coil L2 detects the position of the power reception device itself by receiving signals from the power transmission coil. The system uses the existing electromagnetic field interaction for self-positioning without requiring additional dedicated detection components, allowing the device to determine its own position using its primary power reception component
2Measurement precision
If a coil L3 is added to the power reception device 200 for position detection, then the position detection capability is improved, but interference occurs between the resonance coil L2 and the coil L3
Solution Approach 1:
The power reception coil L2 is made to serve dual purposes: both receiving power from the power transmission coil and detecting the position of the power reception device. By utilizing the same coil for both power reception and position detection functions, the patent eliminates the need for a separate detection coil L3, thereby avoiding the need to manage interference between multiple coils
Solution Approach 2:
The patent extracts the position detection function from a separate coil L3 and integrates it into the existing power reception coil L2. This extraction eliminates the harmful interference between separate coils while maintaining the position detection capability through signal processing of the electromagnetic interactions
3Length of stationary object
If multiple power feeding coils L1 are arranged in a matrix shape for power transmission, then the power feedable distance is extended, but the complexity of the system increases
Solution Approach 1:
The power transmission system is divided into multiple independent power transmission coils L1 arranged in a matrix. Each coil can be independently controlled and optimized, allowing the system to extend power transmission distance by activating only the necessary subset of coils based on the position of the power reception device, thereby managing complexity through modular independent units
Solution Approach 2:
The system dynamically selects and activates only the power transmission coils L1 that are necessary for the current position of the power reception device. This dynamic control approach allows the system to maintain extended power feedable distance through the matrix arrangement while managing complexity by activating only a subset of coils at any given time rather than operating all coils simultaneously
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 enables stable and efficient power transmission and reception while maintaining the mobility of the moving body by accurately determining the positional relationship between power transmission and reception devices, reducing interference, and optimizing power distribution.
Implementation Method 1
a wireless power feeding system using magnetic field resonance coupling (magnetic field resonance) has been researched and developed. Magnetic field resonance coupling means a state where oscillation of a magnetic field generated by an AC current flowing through a resonance circuit in a power transmission device is transmitted to a resonance circuit in a power reception device to resonate so that magnetic fields respectively generated by coils of the resonance circuits are firmly coupled to each other
Implementation Method 2
a position estimation device that estimates a position of the power reception coil relative to the power transmission devices on the basis of the strength of the AC signal that has propagated from the power reception coil to each of the power transmission devices
Data Source
AI summary
A wireless power feeding system and method in which a positional relationship between a power transmission device and a power reception device is grasped to perform power transmission and reception without deteriorating the mobility of a moving body on which the power reception device is mounted. The system transmits power using a magnetic field resonance method includes power transmission devices including power transmission coils, a power reception device including a power reception coil that receives AC power having a first frequency from each of the power transmission coils and a transmission circuit that outputs an AC signal having a second frequency different from the first frequency and transmits the AC signal from the power reception coil, and a position estimation device that estimates a position of the power reception coil relative to the power transmission devices based on the strength of the AC signal from the power reception coil to the power transmission devices.