Magnetic Insulator Coatings for 3D Flux Lamination Stacks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional coatings on electrical steel used in transformer cores and electric machine laminations restrict magnetic flux to only the tangential direction, leading to low stack saturation flux density and limited magnetic permeability in the normal direction.
Innovation Solution
Applying a ferromagnetic or ferrimagnetic coating with a relative magnetic permeability of 500 to 20,000 on both sides of electrical steel sheets, allowing for magnetic flux in both the stack normal and tangential directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional insulating coatings are applied to electrical steel sheets, then electrical insulation is provided and eddy current losses are reduced, but magnetic flux is restricted to tangential direction only and stack saturation flux density is reduced
Solution Approach 1:
The patent changes the magnetic parameter (permeability) of the coating material from conventional non-magnetic (μr=1) to ferromagnetic/ferrimagnetic (μr=500-20,000). This parameter change allows the coating to provide electrical insulation while simultaneously supporting magnetic flux in the normal direction, thereby increasing stack saturation flux density without compromising eddy current loss reduction
Solution Approach 2:
The patent employs composite coating materials that combine electrical insulation properties with ferromagnetic/ferrimagnetic characteristics. Examples include ferrite-based coatings (MnZn ferrite, NiZn ferrite, MgMnZn ferrite, CoNiZn ferrite, Co ferrite, Ni ferrite) and Yttrium iron garnet (Y3Fe5O12), which integrate both insulating and magnetic functionalities in a single coating layer
2Reliability
If conventional insulating coatings are applied to electrical steel sheets, then electrical insulation is provided, but magnetic permeability in the normal direction is limited
Solution Approach 1:
The patent changes the magnetic parameter (permeability) of the coating material from conventional non-magnetic (μr=1) to ferromagnetic/ferrimagnetic (μr=500-20,000). This parameter change allows the coating to provide electrical insulation while simultaneously supporting magnetic flux in the normal direction, thereby increasing stack saturation flux density without compromising eddy current loss reduction
Solution Approach 2:
The patent employs composite coating materials that combine electrical insulation properties with ferromagnetic/ferrimagnetic characteristics. Examples include ferrite-based coatings (MnZn ferrite, NiZn ferrite, MgMnZn ferrite, CoNiZn ferrite, Co ferrite, Ni ferrite) and Yttrium iron garnet (Y3Fe5O12), which integrate both insulating and magnetic functionalities in a single coating layer
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 magnetic insulator coatings enable higher magnetic permeability and saturation flux density, allowing for a 3D flux path and improved performance in electrical apparatus, particularly in transformer cores and electric machine laminations.
Implementation Method 1
The ferromagnetic or ferrimagnetic coating applied to both sides of the electrical steel sheets has a relative magnetic permeability of between μr=500 to 20,000
Implementation Method 2
allowing for magnetic flux in both the stack normal and tangential directions
Implementation Method 3
Electrical steel used in cores of electrical apparatus such as transformers, inductors, stators and rotors of electric machines are stamped to make laminations to form cores. Electrical steel used to make cores is usually coated with insulation on both sides of the electrical steel sheets to reduce eddy current losses
Data Source
AI summary
A core for an electrical apparatus includes a plurality of electrical steel sheets having a ferromagnetic or ferrimagnetic coating applied to both sides of the electrical steel sheets. The electrical steel sheets are arranged in a stack to form a laminated stack. The ferromagnetic or ferrimagnetic coating is applied to both sides of the electrical steel sheets. The coating may comprise MnZn ferrites, NiZn ferrites, MgMnZn ferrites, CoNiZn ferrites, Co ferrites, Ni ferrites, Yttrium iron garnets (Y3Fe5O12) or other ferromagnetic or ferrimagnetic coating materials.