Multi-Coil Wireless Power Unit for Leakage Field Cancellation
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Solution Overview
Problem
Wireless power transmission systems face inefficiencies due to displacement between power feeding and receiving coils, leading to reduced magnetic coupling and unwanted leakage magnetic fields, which can cause electromagnetic interference.
Innovation Solution
A coil unit configuration with a first and second coil, a third coil on the rear side of the first coil, and a fourth coil on the rear side of the second coil, where the axial directions of the third and fourth coils are nonparallel to the first and second coils, and a drive control unit controls the current phases to match interlinked magnetic flux and generate opposing flux for cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple cores are disposed in a plane with intervals to serve as an enlarged core, then robustness to displacement is improved, but unwanted leakage magnetic field is increased
Solution Approach 1:
The coil unit is divided into multiple independent coils (first coil, second coil, third coil, fourth coil) arranged in a specific configuration. Each coil contributes to the overall magnetic field while the segmentation allows for better control of flux distribution, reducing leakage fields compared to a single large core structure.
Solution Approach 2:
The invention converts the potentially harmful leakage magnetic field into a beneficial effect by using the third and fourth coils to generate opposing magnetic flux that cancels out the unwanted leakage fields from the first and second coils, while maintaining the displacement robustness provided by the multi-coil structure.
2Power
If a large current flows through the coil to meet high-power transmission demand, then power transmission capability is improved, but leakage magnetic field strength is increased
Solution Approach 1:
The third and fourth coils act as intermediary elements that mediate between the high-power transmission requirement and the leakage field problem. By controlling the current phases in these coils, the system can achieve high power transmission while the opposing magnetic flux from these intermediary coils cancels out the harmful leakage fields.
Solution Approach 2:
The invention changes the phase parameters of currents in different coils to achieve both high power transmission and reduced leakage fields. By adjusting the phase relationships between currents in the first, second, third, and fourth coils, the system optimizes power transmission capability while minimizing harmful electromagnetic radiation.
3Stability of the object's composition
If the axial direction of the third and fourth coils is nonparallel to the first and second coils, then magnetic flux circulation in locations away from the coil unit is improved, but device complexity is increased
Solution Approach 1:
The third and fourth coils are oriented with axial directions nonparallel to the first and second coils, introducing a dimensional change in the magnetic flux circulation paths. This three-dimensional arrangement allows magnetic flux to circulate more effectively in locations away from the coil unit, improving field distribution and reducing leakage effects.
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 reduces unwanted leakage magnetic fields while maintaining magnetic coupling efficiency even with coil displacement, minimizing electromagnetic interference.
Implementation Method 1
wireless power transmission technology that utilizes an electromagnetic induction effect between a primary (power feeding) coil and a secondary (power receiving) coil that face each other to transmit power without any mechanical contact
Implementation Method 2
The drive control unit controls a direction or phase of a current flowing in each of the first coil, the second coil, the third coil, and the fourth coil
Data Source
AI summary
A coil unit includes first and second coils that are apposed, and third and fourth coils located on the rear side of the first and second coils so as to interpose the center of the first coil and the center of the second coil between the third and fourth coils, in the direction of alignment of the first and second coils. The axial direction of the third and fourth coils is substantially perpendicular to the axial direction of the first and second coils. First to fourth drive control units control the directions or phases of the currents to be supplied to the first to fourth coils, respectively.