Nanoparticle Polymer Insulation for Low-Conductivity HVDC Cables
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polymer compositions used in high voltage direct current (HVDC) cables have relatively high direct current (DC) electrical conductivity, which increases heat generation and poses a risk of thermal runaway and electric breakdown when voltage is increased, and they often rely on peroxides for crosslinking, leading to undesirable by-products and complex production processes.
Innovation Solution
A polymer composition comprising a blend of low density polyethylene (LDPE), polypropylene, and an aliphatic functionalized inorganic nanoparticle filler, which achieves exceptionally low DC conductivity without the need for peroxides, thereby reducing heat generation and simplifying the production process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the voltage of HVDC cables is increased to increase power transmission capacity, then the power transmission capacity is improved, but heat generation increases leading to thermal runaway risk
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer insulation material by incorporating specific nanoparticle fillers (silica, alumina, titania) at controlled concentrations (0.1-10 wt%). This modifies the electrical and thermal properties of the insulation, reducing DC conductivity and improving heat dissipation characteristics, thereby enabling higher voltage operation without excessive heat generation
Solution Approach 2:
The patent creates a composite polymer material by combining conventional insulation polymers (PE, PP, PVDF, EVOH) with inorganic nanoparticle fillers. This composite structure leverages the electrical insulation properties of the polymer matrix and the thermal conductivity and electrical resistance properties of the nanoparticle dispersion, achieving reduced heat generation while maintaining electrical insulation at higher voltage levels
2Strength
If peroxides are used for crosslinking to improve mechanical properties, then mechanical strength is improved, but decomposition products are formed causing unpleasant odour and negative influence on electrical properties
Solution Approach 1:
The patent removes peroxide crosslinking agents from the composition entirely, replacing them with nanoparticle-based reinforcement mechanisms. The mechanical strength is achieved through the composite structure and nanoparticle-polymer interactions rather than chemical crosslinking, thereby eliminating the source of harmful decomposition products
Solution Approach 2:
The patent replaces complex peroxide-based crosslinking chemistry with simpler physical reinforcement using nanoparticle fillers. This substitution uses inexpensive, inert inorganic particles that do not decompose, eliminating the need for complex crosslinking reactions and their associated harmful by-products
3Temperature
If peroxide crosslinking is performed to improve heat and deformation resistance, then thermal resistance is improved, but a time and energy consuming degassing step is required
Solution Approach 1:
The patent extracts the crosslinking step entirely from the processing sequence by using nanoparticle-reinforced thermoplastic polymers that achieve thermal resistance through composite structure rather than chemical crosslinking. This eliminates the subsequent degassing step required to remove peroxide decomposition products, reducing both production time and energy consumption
Solution Approach 2:
The patent skips the crosslinking and degassing steps by using a nanoparticle-filled thermoplastic composition that achieves the desired thermal and mechanical properties through physical reinforcement. This allows direct extrusion and processing without intermediate chemical treatment steps, significantly accelerating production
Data Source
AI summary
A polymer composition comprising (i) 4.95 to 95.0 wt. % low density polyethylene (LDPE) (component (i), herein after); (ii) 4.95 to 95.0 wt. % of a polypropylene (component (ii), herein after); and (iii) 0.00 to 30.0 wt. % of a styrene block copolymer (component (iii), herein after); (iv) 0.05 to 10.0 wt. % of an aliphatic, preferably alkyl, functionalized inorganic nanoparticle filler (component (iv), herein after); whereby the weight percentages (wt. %) are expressed relative to the total weight of the polymer composition.