HVDC Cable Insulation Composition Without Peroxide Crosslinking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High voltage DC cables face challenges with thermal runaway due to high insulation conductivity, leading to electric breakdown, and existing crosslinking methods using peroxides result in undesirable by-products and increased production costs.
Innovation Solution
A polymer composition comprising low density polyethylene (LDPE), polypropylene, and a styrene block copolymer, which eliminates the need for peroxides and reduces DC conductivity, thereby allowing for higher operating temperatures and simplified cable production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If peroxides are used for crosslinking to improve heat and deformation resistance, then mechanical strength and chemical resistance are improved, but volatile decomposition products are formed which negatively influence electrical properties and require time-consuming degassing steps
Solution Approach 1:
The invention extracts and eliminates peroxides from the cable insulation system entirely. By using pure polyethylene without peroxide crosslinking agents, the harmful volatile decomposition products are completely avoided, and the degassing step becomes unnecessary while maintaining adequate mechanical properties through optimized polyethylene composition and processing.
2Temperature
If crosslinking is performed to improve dimensional stability at elevated temperatures, then heat resistance is improved, but the process becomes more complex and costly with additional degassing steps
Solution Approach 1:
The invention removes the crosslinking process entirely from the cable manufacturing workflow. By relying on high-quality polyethylene with optimized molecular weight and branching structure, the material achieves sufficient thermal stability without requiring peroxide crosslinking or subsequent degassing operations, thereby simplifying the overall process.
Solution Approach 2:
The invention optimizes key parameters of the polyethylene itself - specifically molecular weight distribution, branching density, and comonomer content - to achieve the desired dimensional stability at elevated temperatures without chemical crosslinking. This parameter optimization allows the thermoplastic material to perform adequately in the absence of crosslinked network structure.
3Reliability
If peroxides are used for crosslinking to improve chemical resistance and abrasion resistance, then durability is improved, but unpleasant odours and volatile by-products are generated during the process
Solution Approach 1:
The invention completely extracts peroxides from the system, eliminating the source of unpleasant odours and volatile by-products. The polyethylene is processed and installed without any crosslinking agents, ensuring no odorous decomposition products are generated during manufacturing or cable operation, while chemical resistance is maintained through proper material selection and design.
Data Source
AI summary
A cable, preferably a power cable, comprising one or more conductors surrounded by at least one layer, wherein said layer comprises (i) 15 to 84.5 wt % low density polyethylene (LDPE); (ii) a polypropylene; and (iii) a styrene block copolymer; wherein the weight percentages are based on the layer as a whole.