Stacked PCB EV Charging Coil With Cooling Insert Boards
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Solution Overview
Problem
Existing wireless inductive charging systems for electric vehicles face challenges with the use of Litz wire coils, which are costly, heavy, and require manual assembly, necessitating a more efficient and compact design for the receiver to minimize vertical size while maintaining effective power transfer.
Innovation Solution
A modular PCB-based coil design featuring stacked coil boards with electrically-insulating and thermally-conductive insert boards, including microchannels for cooling, arranged in parallel to generate power when exposed to a changing magnetic field, reducing material costs and weight while optimizing vertical space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Litz wire coils are used to construct the receiver, then power transfer capability is achieved, but material cost increases, weight increases, and manual assembly is required
Solution Approach 1:
The receiver is divided into multiple PCB coil boards stacked vertically, with each board containing a simplified copper trace winding pattern. This segmentation allows mass production of individual boards and simplifies assembly compared to manual Litz wire winding, while maintaining power transfer capability through the stacked configuration
Solution Approach 2:
The mechanical process of manually winding and assembling Litz wire coils is replaced with PCB fabrication processes for creating copper trace windings. The PCB manufacturing process automates the winding pattern creation, eliminating manual assembly steps and reducing labor complexity
2Reliability
If Litz wire coils are used to construct the receiver, then power transfer capability is achieved, but weight increases
Solution Approach 1:
The design uses standard PCB materials and copper traces instead of expensive and heavy Litz wire. The PCB coil boards use conventional printed circuit board substrates and copper layers, significantly reducing weight while maintaining electrical functionality for power transfer
Solution Approach 2:
The receiver employs composite construction using PCB substrate materials combined with copper trace windings, separated by electrically insulating layers. This composite structure achieves the necessary electrical properties for inductive power transfer while minimizing weight compared to solid Litz wire construction
3Power
If multiple coil boards are stacked in parallel, then power transfer efficiency is improved, but thermal management becomes more challenging
Solution Approach 1:
Electrically insulating layers are placed between adjacent coil boards to prevent electrical breakdown and short circuits. These intermediary layers provide electrical isolation while allowing magnetic field penetration, enabling safe stacking of multiple high-power coil boards
Solution Approach 2:
Thin electrically insulating films or layers are used between coil boards to provide electrical isolation. These thin barriers prevent arcing and electrical breakdown while maintaining compact stacking and allowing efficient magnetic coupling between adjacent coils
4Length of moving object
If vertical stacking of coil boards is implemented, then receiver height is reduced, but electrical breakdown risk increases
Solution Approach 1:
Electrically insulating layers are positioned between adjacent coil boards to prevent electrical breakdown and short circuits. These intermediary layers provide electrical isolation while allowing magnetic field penetration, enabling safe stacking of multiple high-power coil boards
Solution Approach 2:
The design transitions from horizontal wire winding to vertical stacking of planar PCB coils. This dimensional change allows compact height while distributing electrical stress across multiple isolated layers, reducing breakdown risk through the insulating barriers between stacks
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 modular design enhances power transfer efficiency, reduces weight and material costs, and provides effective cooling, thereby improving the overall performance and reliability of wireless inductive charging systems for electric vehicles.
Implementation Method 1
a first metallic trace forming a first inductive winding disposed on a first surface of the substrate... arranged in a stacked formation to generate electric power when exposed to a changing magnetic field
Implementation Method 2
the insert board including an electrically-insulating and thermally-conductive material, the insert board including a plurality of microchannels to provide cooling to the first and second coil boards
Data Source
AI summary
A wireless inductive charging apparatus includes first and second coil boards arranged in parallel, each coil board having a substrate and a first metallic trace forming a first inductive winding disposed on a first surface of the substrate. The apparatus includes an electrically-insulating and thermally-conductive insert board arranged between and adjacent to the first and second coil boards, the insert board including microchannels to provide cooling to the coil boards. The first coil board, the insert board and second coil board are arranged in a stacked formation to generate electric power when exposed to a changing magnetic field. Each coil board can also include a second metallic trace forming a second inductive winding disposed on a second surface of the substrate, the second surface on an opposite side of the substrate relative to the first surface. Additional coil boards and insert boards can be added to the stacked arrangement.