Wireless Charging Coil Alignment Using Self-Inductance Sensing
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Solution Overview
Problem
Conventional wireless charging technologies face inefficiencies due to position deviations between transmitting and receiving coils, which can lead to reduced charging efficiency and inaccurate foreign matter detection when additional coil matrices are used for alignment.
Innovation Solution
A wireless charging device that aligns transmitting and receiving coils using self-inductance and resonant frequency monitoring, without additional coil matrices, to adjust the position of the transmitting coil automatically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a small coil matrix is added on the transmitting coil for position detection, then automatic alignment capability is improved, but charging efficiency deteriorates due to extra loss
Solution Approach 1:
The patent extracts the position detection function from the traditional small coil matrix approach and implements it using the existing transmitting coil by monitoring changes in self-inductance and resonant frequency. This eliminates the need for additional detection coils while maintaining automatic alignment capability, thereby avoiding the extra energy loss that would be introduced by additional coil components.
Solution Approach 2:
The transmitting coil is made to serve multiple functions: it simultaneously performs wireless power transmission and position detection for automatic alignment. By monitoring the self-inductance and resonant frequency of the transmitting coil, the system can detect position deviations without requiring separate detection coils, thus avoiding the energy loss associated with additional coil matrices.
2Extent of automation
If a small coil matrix is added on the transmitting coil for position detection, then automatic alignment capability is improved, but foreign matter detection accuracy deteriorates
Solution Approach 1:
The patent removes the small coil matrix that interfered with foreign matter detection and instead uses the existing transmitting coil's electrical characteristics (self-inductance and resonant frequency) for position detection. This extraction of the detection function to the transmitting coil itself eliminates the interference that additional metal coils would cause in foreign matter detection accuracy.
Solution Approach 2:
The transmitting coil performs self-diagnosis by monitoring its own self-inductance and resonant frequency changes. These parameters naturally vary with position deviations and can indicate both alignment status and foreign matter presence, eliminating the need for separate detection coils that would introduce metal interference and reduce detection accuracy.
3Productivity
If the transmitting coil is controlled to move for alignment, then charging efficiency is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical alignment mechanisms with an electrical field-based detection and control system. By monitoring self-inductance and resonant frequency changes of the transmitting coil, the system can determine position deviations and control coil movement electronically, avoiding the need for complex mechanical sensors, actuators, and control systems that would increase device complexity.
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
Improves charging efficiency and maintains accurate foreign matter detection by aligning coils based on self-inductance and resonant frequency, enhancing user experience and freedom in wireless charging applications.
Implementation Method 1
a resonant network including a resonant capacitor and a transmitting coil
Implementation Method 2
Wireless transmission of electric energy is implemented between the transmitting coil and the receiving coil through electromagnetic field coupling
Implementation Method 3
uses conductive media such as an electric field, a magnetic field, a microwave, or a laser to implement wireless transmission of electric energy
Data Source
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AI summary
This application discloses a wireless charging device, alignment method, system, and charging base, which are configured to perform wireless charging on electronic devices such as a mobile phone or a wearable device. The wireless charging device includes a resonant network, an inverter circuit, and a controller. The resonant network includes a resonant capacitor and a transmitting coil. An input end of the inverter circuit is configured to connect to a direct current power supply, and an output end of the inverter circuit is configured to connect to the resonant network. The controller is configured to determine a moving direction of the transmitting coil based on a self-inductance of the transmitting coil or a resonant frequency of the resonant network, and control a movement of the transmitting coil based on the moving direction of the transmitting coil, to enable the wireless charging device to align with the electronic device. The self-inductance of the transmitting coil increases along the moving direction of the transmitting coil, and the resonant frequency decreases along the moving direction of the transmitting coil. The wireless charging device implements automatic alignment, thereby improving a degree of freedom for the wireless charging device to perform wireless charging on the electronic devices and improving user experience, without causing an extra loss and affecting accuracy of foreign matter detection.