Tire Relay Coil Shielding for Dynamic Wireless Power Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dynamic wireless power transfer systems face challenges in increasing power transmission efficiency due to the large and varying distance between power transmission and reception coils, especially in applications where the vehicle is moving.
Innovation Solution
Incorporating a relay coil embedded in the vehicle's tire, positioned further outwards than the steel belt, which is covered by a conductive shield, to facilitate efficient power transfer between the power transmission coil in the road and the power reception coil, eliminating the need to consider the distance between them.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a power transmission coil is embedded on the ground side and a power reception coil is mounted under the vehicle floor, then wireless power transfer is achieved, but the distance between the coils is large and varies depending on the vehicle, making it difficult to increase power transmission efficiency
Solution Approach 1:
A relay coil is introduced as an intermediary component embedded in the vehicle tire. This relay coil acts as a mediator between the ground-side power transmission coil and the vehicle-side power reception coil, enabling efficient power transfer by reducing the effective transmission distance and stabilizing the magnetic flux path through the conductive shield.
Solution Approach 2:
The power transmission path is segmented into two stages: first from the ground power transmission coil to the relay coil in the tire, and second from the relay coil to the power reception coil under the vehicle floor. This segmentation allows each stage to operate at optimized distances, improving overall transmission efficiency.
2Loss of energy
If the relay coil is positioned closer to the power transmission coil to improve efficiency, then power transfer efficiency increases, but the steel belt in the tire may generate harmful eddy currents
Solution Approach 1:
The conductive shield, initially appearing as a potential obstacle, is strategically positioned between the relay coil and the steel belt to block harmful eddy currents. This converts the shield from a passive structural element into an active protective component that eliminates the harmful effect while preserving the beneficial close-proximity power transfer.
Solution Approach 2:
The conductive shield serves as an intermediary barrier between the relay coil's magnetic field and the steel belt. It mediates the interaction by blocking the magnetic flux from penetrating the steel belt, thereby preventing eddy current generation while allowing the relay coil to maintain its optimal position for efficient power transfer.
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 enhances power transfer efficiency by stabilizing the magnetic flux and reducing eddy currents, allowing for reliable and efficient electric power delivery to the vehicle while it is in motion.
Implementation Method 1
electric power is transferred from the power transmission coil to the power reception coil through the relay coil
Implementation Method 2
a relay circuit that transfers electric power between the power transmission coil and the power reception coil. The relay circuit includes a relay coil that is provided in a tire of the vehicle
Implementation Method 3
the steel belt is covered by a conductive shield
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A dynamic wireless power transfer system (500) includes: a power transmission coil (40) that is provided in a road (105); a power transmission circuit (30) that supplies electric power to the power transmission coil; a power reception coil (240, 240r) that is provided in a vehicle (202); a power reception circuit (230) that is connected to the power reception coil; and a relay circuit (70) that transfers electric power between the power transmission coil and the power reception coil in a contactless manner.