Grain-Oriented Electrical Steel Sheet Noise Reduction
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Solution Overview
Problem
Grain-oriented electrical steel sheets subjected to magnetic domain refining treatments still produce significant noise when assembled into transformers, despite efforts to reduce iron loss.
Innovation Solution
A grain-oriented electrical steel sheet with a forsterite film and tension coating on both surfaces, undergoing magnetic domain refining treatment with linear thermal strain applied by laser or electron beam irradiation, achieving specific deflection curvatures to minimize noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If magnetic domain refining treatment is applied to reduce iron loss, then iron loss is reduced, but transformer noise increases
Solution Approach 1:
The patent applies laser beam irradiation to induce thermal strain in the steel sheet surface, changing the physical parameters of the material to refine magnetic domain structure. By controlling the laser power, scanning speed, and irradiation pattern, the patent optimizes the balance between iron loss reduction and noise generation, achieving both low iron loss and low noise performance through precise parameter adjustment of the thermal processing
2Reliability
If high degree of crystal grain orientation is achieved, then magnetic properties are improved, but iron loss increases
Solution Approach 1:
The patent applies local quality by introducing thermal strain through laser beam irradiation at specific locations and orientations on the steel sheet surface. This creates localized modifications to the crystal grain structure and magnetic domain distribution, achieving optimal magnetic properties in critical areas while maintaining low iron loss through controlled local structural changes rather than uniform global treatment
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 solution significantly reduces noise in transformers by optimizing the magnetic domain structure and stress distribution within the steel sheets, enhancing their noise properties when used in transformer iron cores.
Implementation Method 1
a laser beam is irradiated in a direction intersecting the rolling direction of the steel sheet
Implementation Method 2
introducing a thermal strain region in a direction crossing a rolling direction of the steel sheet
Implementation Method 3
the linear thermal strain is applied by electron beam irradiation
Implementation Method 4
a combined film tension of the forsterite film and the tension coating is equivalent on both surfaces of the steel sheet
Data Source
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AI summary
Provided is a grain-oriented electrical steel sheet, with reduced iron loss by magnetic domain refining treatment, exhibiting an excellent noise property and effectively reducing noise generated when stacked in an iron core of a transformer. In a grain-oriented electrical steel sheet including a forsterite film and a tension coating on both surfaces, magnetic domain refining treatment has been performed to apply linear thermal strain to the grain-oriented electrical steel sheet, the magnitude of deflection in the rolling direction of the steel sheet is 600 mm or more and 6000 mm or less as the curvature radius of the deflected surface with the surface having the strain applied thereto being the inner side, and the magnitude of deflection in the direction orthogonal to the rolling direction is 2000 mm or more as the curvature radius of the deflected surface with the surface having the strain applied thereto being the inner side.