Semiconductive Cable Tape Extraction for XLPE Dielectric Protection
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Solution Overview
Problem
Existing methods for manufacturing medium- and high-voltage electric cables using cross-linked polyethylene insulating systems are prone to degradation due to the migration of undesirable chemical species, particularly water, which increases electrical conductivity and reduces dielectric performance, posing a threat to the reliability and economic stability of energy transmission networks.
Innovation Solution
A method involving the use of a flexible tape formed from materials like woven or non-woven polymers, which is subjected to an extraction process to remove undesirable chemical species, such as water, before or during application around the cable core, thereby forming a barrier to prevent migration and maintain dielectric performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a tape is applied around the cable core to provide mechanical protection and barrier function, then the mechanical strength and protection of the cable are improved, but undesirable chemical species from the tape can migrate into the insulating system and increase electrical conductivity, worsening dielectric performance
Solution Approach 1:
The tape undergoes a preliminary extraction treatment before being applied to the cable core. This treatment removes undesirable chemical species (such as water, plasticizers, and additives) from the tape in advance, preventing their subsequent migration into the insulating system. The extraction process creates a cleaner tape that maintains mechanical protection functions without compromising dielectric performance.
Solution Approach 2:
Undesirable chemical species are extracted and removed from the tape material before application. This extraction process separates the harmful components (water, plasticizers, additives) from the beneficial structural components of the tape, allowing the tape to provide mechanical strength without introducing contaminants that would degrade dielectric properties.
2Object-affected harmful factors
If the cable operates in humid environments, then the cable must provide adequate protection against moisture ingress, but moisture can migrate into the insulating system and increase electrical conductivity, reducing dielectric strength
Solution Approach 1:
The tape is pre-treated through extraction to remove hygroscopic substances and undesirable chemical species before being applied to the cable. This preliminary action ensures that the tape itself does not become a source of moisture or chemical contaminants that could migrate into the insulating system under humid operating conditions.
Solution Approach 2:
The extraction process creates a chemically inert tape by removing reactive and hygroscopic components. The treated tape forms a stable barrier that resists moisture absorption and chemical migration, maintaining dielectric strength even when the cable operates in humid environments.
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 limits the loss of dielectric performance and extends the lifespan of the cables by preventing the migration of undesirable chemical species, particularly in humid environments, thus ensuring the reliability and efficiency of energy transmission.
Implementation Method 1
said extraction step being a step of heating the tape and of vaporising at least partially at least one of the undesirable chemical species
Implementation Method 2
said tape being adapted to prevent a migration and a progression of water in the longitudinal direction of the electric cable
Data Source
Figure 1~2
AI summary
The invention relates to a method for manufacturing a mediumor high-voltage electric cable, of the type comprising: - a core formed of an elongate electrically conductive element and of an insulating system comprising at least one layer comprising at least one cross-linked polyethylene, said at least one layer being arranged coaxially around the elongate electrically conductive element, and - a tape enveloping the core the tape being formed of a semiconductor polymer material., characterised in that the method comprises at least one step of extracting at least one chemical species from the tape, said chemical species being a chemical species able to reach the insulating system by migration from the tape and to decrease the dielectric performance of the insulating system.