Dual-Layer Elastomeric Cable Spacer Clamp Liner
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing clamp liners for spacer clamp arms in high voltage power transmission systems are inadequate for composite core conductors operating at temperatures above 130°C, as they fail to provide effective electrical semi-conductive properties and slip resistance without damaging the conductive cables, especially under high tension and vibration.
Innovation Solution
A dual-layer clamp liner with a semi-conductive fluoroelastomer compound configuration, comprising an outer portion made from ethylene propylene diene monomer (EPDM) and an inner portion from vinylidene fluoride hexafluoropropylene (FKM), providing a secure grip and slip resistance up to 200°C, and optionally using perfluoroelastomer (FFKM) for higher temperatures, with a design that allows 15% compression to maintain corona-free performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-material clamp liner is used, then the manufacturing cost is low and the structure is simple, but it cannot simultaneously withstand high temperatures and provide good electrical semi-conductive properties
Solution Approach 1:
The clamp liner uses a composite structure with an inner layer of semi-conductive elastomer (providing electrical semi-conductive properties) and an outer layer of high-temperature resistant elastomer (providing thermal stability). This composite material approach allows the liner to simultaneously achieve both electrical semi-conductivity and high-temperature resistance, resolving the contradiction between reliability and material performance limitations.
Solution Approach 2:
The clamp liner is divided into two distinct functional layers: an inner layer specifically designed for electrical semi-conductivity and an outer layer optimized for high-temperature resistance. This segmentation allows each layer to perform its specialized function independently, enabling the overall liner to meet both electrical and thermal requirements that a single material could not satisfy.
2Temperature
If silicone rubber is used for high temperature resistance, then the temperature withstand capability is improved, but the electrical semi-conductive properties deteriorate
Solution Approach 1:
The solution combines silicone rubber (or other high-temperature resistant elastomers) as the outer layer for thermal stability with a semi-conductive elastomer as the inner layer for electrical performance. This composite approach allows the liner to withstand temperatures exceeding 120°C while maintaining the necessary electrical semi-conductive properties, directly resolving the contradiction between temperature resistance and electrical functionality.
3Strength
If a metal spacer clamp arm is used, then the structural strength is improved, but the risk of corona discharge and electrical stress increases
Solution Approach 1:
The semi-conductive elastomer liner acts as an intermediary layer between the metal spacer clamp arm and the conductive cable. This intermediate layer provides a controlled electrically semi-conductive path that reduces electrical stress concentration and prevents corona discharge, while the metal clamp arm maintains its structural strength. The intermediary layer thus resolves the contradiction by decoupling the structural function from the electrical function.
Solution Approach 2:
The liner modifies the electrical parameters at the interface between the metal clamp and the cable by providing a semi-conductive pathway. This changes the electrical field distribution, reducing peak electric field intensity and preventing corona discharge, while the metal clamp arm continues to provide mechanical strength. The parameter change in electrical conductivity at the interface resolves the contradiction between strength and electrical safety.
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 improved clamp liner effectively grips and protects composite core conductors at high temperatures, maintaining slip resistance and electrical resistance while preventing damage, achieving corona-free performance at 340 kV phase to ground and extending service life by resisting ozone for over 10 years.
Implementation Method 1
providing a secure grip and slip resistance up to 200°C
Implementation Method 2
maintaining slip resistance and electrical resistance while preventing damage
Implementation Method 3
conductive cable temperatures often exceed the limit of the known clamp liner. Silicone rubbers can withstand the relatively high surface temperatures
Implementation Method 4
provide a controlled electrically semi-conductive path between the spacer clamp and the frame
Implementation Method 5
maintaining slip resistance and electrical resistance
Implementation Method 6
The spacer clamp arms permit a limited amount of movement of the spacer clamp arms with respect to the frame
Implementation Method 7
reduce the possibility of the conductive cables contacting one another, the generation of corona discharge, and the creation of electrical stress and interference
Data Source
AI summary
A liner for use with a cable spacer clamp arm is provided. The liner includes a first portion formed in an arcuate configuration and made from a first elastomeric material. A second portion is formed in the arcuate configuration and is receivable within the first portion. The second portion is made from a second elastomeric material different from the first elastomeric material. The first portion attaches to the second portion.