Capacitive Wireless Power Transfer With Reference Potential Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless power transmission systems face challenges in stabilizing the potential difference between power transmitting and receiving apparatuses, leading to malfunctions, especially when a touch panel is operated during charging, due to the strong electric field formed by active electrodes, which requires high accuracy in positional relationships and larger apparatus sizes.
Innovation Solution
A wireless power transmission system with a power transmitting apparatus and a power receiving apparatus, featuring active, passive, and reference potential electrodes, where the reference potential is stabilized by capacitively coupling the electrodes and using transformers to manage voltage, reducing parasitic capacitance and allowing for efficient power transmission without malfunctions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If electric-field coupling is used with active electrodes placed close to each other to form a strong electric field, then high-efficiency power transmission is achieved, but the strong electric field causes malfunctions when touch panel is operated during charging
Solution Approach 1:
The electrode system is segmented into four distinct electrodes: power transmitting side active electrode, power transmitting side passive electrode, power receiving side active electrode, and power receiving side passive electrode. This segmentation allows independent control of power transmission function and reference potential stabilization function, resolving the contradiction between achieving strong electric field for efficient power transmission and preventing electric field interference during touch panel operation
Solution Approach 2:
The power receiving side passive electrode acts as an intermediary element that provides a stable reference potential to the power receiving apparatus. By introducing this intermediary electrode connected to the external ground, the system stabilizes the reference potential during power reception, preventing malfunctions caused by electric field interference while maintaining the strong electric field between active electrodes for efficient power transmission
2Productivity
If magnetic-field coupling is used to transmit power, then power transmission is achieved, but high-accuracy relative positional relationship between primary and secondary coils is required
Solution Approach 1:
The patent replaces the magnetic-field coupling system with an electric-field coupling system using capacitive electrodes. This substitution eliminates the need for high-accuracy relative positional relationship between coils, as the electric field coupling between planar electrodes is less sensitive to positional misalignment compared to magnetic coupling between coils
Solution Approach 2:
The invention changes the fundamental parameter of power transmission from magnetic field coupling to electric field coupling. By using capacitive electrodes with appropriate area and spacing, the system achieves power transmission with relaxed positional accuracy requirements compared to magnetic coil systems
3Productivity
If coils are used for magnetic-field coupling power transmission, then power transmission is achieved, but the size of the apparatuses cannot be reduced
Solution Approach 1:
The patent substitutes traditional magnetic coils with planar capacitive electrodes for power transmission. This replacement enables significant size reduction because planar electrodes can be integrated into thin printed circuit boards, eliminating the need for bulky coil structures while maintaining power transmission functionality
Solution Approach 2:
The invention uses thin film-like planar electrodes that can be fabricated on substrates, allowing the power transmission apparatus to achieve a thin and compact form factor. This approach replaces the three-dimensional coil structure with two-dimensional planar structures, significantly reducing the overall apparatus volume
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
The system stabilizes the reference potential of the power receiving apparatus, preventing malfunctions and enabling high-efficiency power transmission, even when a touch panel is operated during charging, while allowing for smaller apparatus sizes and reduced parasitic capacitance.
Implementation Method 1
the power transmitting side active electrode and the power receiving side active electrode face each other with an insulator therebetween and are capacitively coupled to each other, whereby power is transmitted from the power transmitting apparatus to the power receiving apparatus
Implementation Method 2
the power transmitting side reference potential electrode and the power receiving side reference potential electrode face each other... the reference potential of the power receiving apparatus is connected to the reference potential of the power transmitting apparatus through the power transmitting side and power receiving side reference potential electrodes
Data Source
AI summary
A power transmitting apparatus includes an active electrode, a passive electrode, a voltage generating circuit that applies a voltage between the active electrode and the passive electrode, and a reference potential electrode connected to a reference potential. A power receiving apparatus includes an active electrode, a passive electrode, a secondary battery connected between the active electrode and the passive electrode, and a reference potential electrode connected to a reference potential. Power is transmitted from the power transmitting apparatus to the power receiving apparatus as a result of the respective electrodes facing each other and being capacitively coupled to each other when the power receiving apparatus is mounted to the power transmitting apparatus.