PCB Stator Windings Reducing Eddy Current Losses
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Solution Overview
Problem
Current electric motors and generators face issues with unwanted heat generation, mechanical failure, and efficiency reduction due to parasitic and eddy currents caused by high current densities in printed circuit board (PCB) windings, leading to structural damage and reduced power output.
Innovation Solution
The implementation of a planar composite structure with radially extending conductive traces connected in loops on a dielectric layer, utilizing a specific interconnect design characterized by a Corner Equation to reduce current density concentrations and minimize parasitic and eddy current effects, thereby reducing resistance and losses in the windings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high current density is used in PCB windings to increase power output, then power output increases, but parasitic and eddy currents are generated causing heat and efficiency loss
Solution Approach 1:
The patent segments the continuous conductive trace into multiple isolated conductive regions separated by dielectric material. This segmentation prevents the formation of large eddy current loops by breaking up the conductive path, thereby reducing parasitic and eddy current losses while maintaining the required current density for power output.
Solution Approach 2:
The patent applies different material properties to different regions: conductive material in regions requiring current flow, and dielectric material in regions where current isolation is needed. This local differentiation of material quality allows optimization of both power transmission and loss reduction in specific areas of the PCB winding.
2Power
If high current density flow is used to enhance power conversion efficiency, then current carrying capacity increases, but temperature gradients increase causing structural damage and delamination
Solution Approach 1:
By segmenting the conductive paths and isolating high current density regions with dielectric material, the patent distributes heat generation more evenly across the PCB structure. This prevents concentrated temperature gradients that would otherwise lead to delamination and structural damage, while maintaining overall current carrying capacity.
Solution Approach 2:
The dielectric material acts as an intermediary between adjacent conductive regions, providing thermal isolation that prevents heat transfer between high current density areas. This intermediary layer reduces temperature gradients and prevents thermal damage to the PCB structure.
3Ease of manufacture
If conventional interconnect designs are used to connect radial traces, then manufacturing is simple, but current density concentrations occur at corners creating electromagnetic interference
Solution Approach 1:
The patent replaces conventional sharp-cornered interconnects with curved or rounded corner designs. This curvature eliminates the current density concentrations that occur at sharp corners, thereby reducing electromagnetic interference and parasitic effects while maintaining ease of manufacture through standard PCB routing techniques.
4Volume of moving object
If adjacent turns and layers are placed close together to reduce device size, then compactness increases, but magnetic field interaction between adjacent windings increases causing losses
Solution Approach 1:
The patent segments adjacent conductive layers with dielectric material to create electromagnetic isolation between turns and layers. This segmentation allows compact positioning while preventing harmful magnetic field interactions, thereby reducing energy losses due to coupling between adjacent windings.
Solution Approach 2:
Dielectric material is used as an intermediary layer between adjacent conductive windings, providing electromagnetic isolation that reduces mutual inductance and magnetic field interaction. This allows compact device design while minimizing energy losses from coupling 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 design effectively reduces loss mechanisms as a function of increasing frequency, enhancing the efficiency and power output of energy conversion devices by minimizing current density concentrations and undesirable electromagnetic fields.
Implementation Method 1
the generation of unwanted heat due to parasitic or eddy currents
Implementation Method 2
the generation of unwanted heat due to parasitic or eddy currents
Implementation Method 3
the interaction between fields from adjacent turns in a winding, and/or windings on adjacent layers
Data Source
AI summary
The disclosure relates to printed circuit board motors and specifically to printed circuit boards used in motors and generators. Windings formed from copper on printed circuit boards have been used for purposes of forming antennas, inductors, transformers, and stators that can be incorporated in permanent magnet brushless DC (permanent magnet synchronous) machines. For energy conversion devices using modern permanent magnet materials and PCB stators, the magnetic field is not strongly confined by magnetically susceptible materials. Thus, the interaction between fields from adjacent turns in a winding, and/or windings on adjacent layers (for a multilayer configuration) may be significant. The structures disclosed hereinafter reduce the effective resistance in the windings, and therefore reduce the associated losses to achieve a reduced current density in portions of the rotating energy conversion devices. The effect of the disclosed structures is a measurable reduction in loss mechanisms as a function increasing frequency, compared to the currently available devices. These effects are significant in frequency ranges important to energy conversion processes as well as typical control strategies, for example, pulse-width modulation.