Nanocomposite Insulation Tape for Electric Tree Resistant Windings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The mica electrical insulating structure in high-voltage formed-wound electrical motors is prone to electric tree progression, which weakens the insulation and reduces the lifetime, particularly due to the vulnerability of the epoxy glass layer outside the mica insulating layer.

Innovation Solution

A method involving the production of a main insulation tape with a nanoparticle-containing joining macromolecular polymer, wound around the conductor, followed by vacuum drawing and impregnation with a macromolecular polymer, creating a structure with nanoparticles concentrated in the fiber reinforcement part to enhance insulation and prevent electric tree progression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a mica insulating tape is impregnated with epoxy resin to form a mica electrical insulating structure, then the insulation can withstand high temperatures, but the epoxy glass layer becomes a weak point that allows electric tree progression

Engineering Contradiction:
Improvetemperature resistanceVSAvoidelectric tree resistance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies different materials with different properties to different regions of the insulating structure. The mica layer provides high-temperature resistance, while the nanocomposite polymer layer (containing 1-100 nm particles) provides enhanced electric tree resistance. This local differentiation of material properties allows each layer to address its specific weakness without compromising the other.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a composite insulating structure by combining mica with a nanocomposite polymer material containing nanoparticles (1-100 nm). This composite approach leverages the high-temperature stability of mica while the nanocomposite polymer provides improved breakdown strength and electric tree resistance, solving the contradiction between temperature resistance and electric tree resistance.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the electric tree progresses dendritically from high electric field concentration parts, then local breakdown occurs, but the insulation lifetime is significantly reduced

Engineering Contradiction:
Improveinsulation integrityVSAvoidinsulation lifetime
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary protective measures by incorporating nanoparticles (1-100 nm) into the polymer impregnating the mica tape before the electric tree can form and progress. The nanocomposite structure creates a more uniform electric field distribution and prevents the dendritic growth of electric trees, thereby preventing local breakdown from progressing into complete insulation failure.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent changes the physical and chemical parameters of the insulating material by introducing nanoparticles (1-100 nm) into the polymer matrix. This nanocomposite modification alters the electrical, mechanical, and thermal properties of the insulation, increasing breakdown strength and suppressing electric tree initiation and progression, thereby extending insulation lifetime.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If an insulating material is used for normal rated voltage 6.6 kV in an inverter-driven motor for rated voltage 3.3 kV, then insulation is available, but the insulation lifetime is significantly reduced due to impulse voltage including inverter surge

Engineering Contradiction:
Improvevoltage compatibilityVSAvoidinsulation lifetime under inverter surge
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the electrical parameters of the insulating material by incorporating nanoparticles (1-100 nm) into the polymer matrix. This nanocomposite modification increases the breakdown strength and impulse voltage resistance of the insulation, allowing it to withstand the high dv/dt surges from inverter operation while maintaining compatibility with the operating voltage.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a nanocomposite insulating material that combines the advantages of conventional insulating polymers with the enhanced electrical properties of nanoparticle reinforcements. This composite structure provides both voltage compatibility and improved resistance to inverter-induced impulse voltages, extending insulation lifetime in inverter-driven motors.

Inventive Principle:
Principle #40Composite materials

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 approach effectively suppresses electric tree progression, prolongs the electrical insulation lifetime, and enhances the mechanical and thermal properties of the insulating structure, improving the reliability of high-voltage electrical machines.

Implementation Method 1

a vacuum drawing step, which is performed after the taping step, of vacuum drawing the tape-wound to-be-insulated object

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

an impregnation step, which is performed after the vacuum drawing step, of injecting a impregnating macromolecular polymer to impregnate the main insulated part therewith

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP3480920B1Method for producing insulating structure
Publication Date: 2023.08.30 TOSHIBA MITSUBISHI ELECTRIC IND SYST CORP
  • EP3480920B1 patent drawingFigure 1
  • EP3480920B1 patent drawingFigure 2
  • EP3480920B1 patent drawingFigure 3

AI summary

An electrical insulating structure producing method for covering an outer surface of a to-be-insulated object. The method comprises: a tape production step (S10) of producing a main insulation tape by using a nanoparticle-containing joining macromolecular polymer; a taping step (S21) of winding a main insulation tape on outside of the to-be-insulated object to form a main insulated part; a vacuum drawing step (S23), which is performed after the taping step, of vacuum drawing the tape-wound to-be-insulated object; and an impregnation step (S24), which is performed after the vacuum drawing step, of injecting a impregnating macromolecular polymer to impregnate the main insulated part therewith.