Nanoparticle-Reinforced Insulation Suppresses Electric Trees
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Solution Overview
Problem
The mica electrical insulating structure in high-voltage formed-wound electrical motors is prone to electric tree formation, which weakens the insulation and reduces the lifespan of the motor, particularly due to the progression of electric trees through the epoxy glass layer rather than the mica layer.
Innovation Solution
A method involving the production of a tape-wound electrical insulating structure with a main insulation layer, fiber reinforcement part, and a macromolecular polymer part containing nanoparticles, where the nanoparticles are concentrated in the fiber reinforcement part, is used. This method includes steps such as sheet production, cutting, winding, vacuum drawing, impregnation with a macromolecular polymer, and solidification to create a robust insulation layer that suppresses electric tree progression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a mica insulating tape impregnated with epoxy resin is used as main insulation, then the insulation can withstand high temperatures and provide electrical insulation, but electric trees are generated and progress through the epoxy glass layer, reducing insulation lifetime
Solution Approach 1:
The patent applies composite materials by combining mica particles (5-50 μm) with nanometer-sized particles (0.01-1 μm) such as SiO2, Al2O3, or TiO2 to create a composite insulating material. This composite structure leverages the high temperature resistance of mica while the nanoparticle-filled epoxy resin matrix prevents electric tree progression, thus resolving the contradiction between temperature resistance and insulation lifetime.
Solution Approach 2:
The patent applies local quality by creating a dual-layer structure where the epoxy glass layer contains a high concentration of nanometer-sized particles specifically at the interface with the mica layer. This localized enhancement of the epoxy layer's properties at the critical interface region prevents electric tree initiation and progression, while maintaining the overall high temperature resistance provided by the mica structure.
2Ease of manufacture
If the epoxy glass layer is used as the primary insulating material, then the insulation can be easily manufactured and applied, but it forms weak points where electric trees progress, reducing overall insulation integrity
Solution Approach 1:
The patent applies parameter changes by modifying the epoxy resin's physical and chemical properties through the addition of nanometer-sized particles. This changes the epoxy layer's electrical and mechanical parameters, transforming it from a weak insulating material prone to electric tree progression into a robust insulating layer that maintains integrity while remaining manufacturable using standard impregnation processes.
Solution Approach 2:
The patent strengthens the epoxy glass layer by creating a composite material system where nanometer-sized particles (0.01-1 μm) are dispersed within the epoxy resin matrix. This composite epoxy layer maintains the ease of manufacture and application characteristics of conventional epoxy insulation while dramatically improving insulation integrity by preventing electric tree progression through the nanoparticle-reinforced structure.
3Reliability
If nanoparticles are uniformly distributed throughout the entire insulating structure, then electrical insulation performance is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies local quality by concentrating nanometer-sized particles specifically in the epoxy glass layer and at the mica-epoxy interface region, rather than uniformly distributing them throughout the entire insulating structure. This localized concentration approach achieves the necessary electrical insulation performance enhancement where it is most critical (at the interface where electric trees typically initiate) while simplifying the manufacturing process and reducing material costs compared to uniform distribution.
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 method effectively suppresses electric tree progression and enhances the electrical insulation lifetime, mechanical strength, and heat conductivity, thereby improving the reliability and efficiency of the electrical insulating structure.
Implementation Method 1
The method effectively suppresses electric tree progression and enhances the electrical insulation lifetime
Implementation Method 2
enhances the electrical insulation lifetime, mechanical strength, and heat conductivity
Implementation Method 3
a vacuum drawing step, which is performed after the taping step, of vacuum drawing the tape-wound to-be-insulated object
Implementation Method 4
a solidifying step, which is performed after the impregnation step, of raising the temperature of the insulated part to solidify the macromolecular polymer containing the nanoparticles
Data Source
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AI summary
A producing method is for an electrical insulating structure covering an outer surface of a to-be-insulated object. The electrical insulating structure producing method comprises: a sheet production step (S12) of producing a main insulation sheet in which nanoparticles have been mixed; a cutting step (S13) in which the main insulation sheet is cut into main insulation tapes; a taping step (S21) of winding each of main insulation tapes on outside of the to-be-insulated object to produce a tape-wound to-be-insulated object in which a main insulated part is formed; a vacuum drawing step (S23) of vacuum drawing the tape-wound to-be-insulated object; an impregnation step (S24) of injecting a impregnating macromolecular polymer to impregnate the main insulated part in the tape-wound to-be-insulated object, and a solidifying step (S25) of raising the temperature of the insulated part to solidify the macromolecular polymer containing the nanoparticles.