The DCP is mainly used as a catalyst, polymerization initiator and vulcanizing agent in the chemical laboratories. The crosslinked polyethylene (XLPE) cable insulation is comprised of low-density polyethylene (LDPE) and percent content of crosslinking agent mainly dicumyl peroxide (DCP). The important material parameters for the microstructure analysis are crystallinity, lamella size, molecular weight and chemical composition. The important mechanical parameters for cable insulation are reliant on the evaluation of elongation rate and permanent elongation. For HVDC cable insulation, the most significant electrical parameters for the evaluation are electrical resistivity, breakdown strength and space charge accumulation.
The growing demand for power transmission poses new challenges for HVDC cables. High voltage direct current (HVDC) transmission technology has received extensive courtesy due to its outstanding performance capability, long-distance transmission and large transmission capacity. It is proven that the role of appropriate DCP content is vital in increasing the DC dielectric performance, internal material characteristics and mechanical performance of XLPE. The space charge accumulation is measured at 30 ☌ under 20–60 kV/mm, resulting in less homo-charges and hetero-charges with the increase in DCP. The DC breakdown strength at 30–90 ☌ is increased due to the increase in crosslinking degree and reduction in carbonyl index/oxidation level. The rise in DCP content increases the crosslinking degree due to which the DC resistivity and activation energy is increased. The increase in DCP in XLPE samples decreases the permanent elongation from 2.2% to 0% and elongation rate from 300% to 80% of the cable insulation. The results of microstructural and chemical composition show that the increase in DCP content increases the crosslinking degree from 74.3% to 81.6%, reduces the crystallinity/lamella thickness from 36.8% to 35.5%/7.6–7.1 nm, reduces the average molecular weight between two crosslinks by 0.01 kg/mol and reduces the oxidation level/carbonyl index. The mechanical properties of XLPE are evaluated by hot-set test. The measurements for the microstructural analysis are taken by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), gel content test and Fourier transform infrared (FTIR). In this research, crosslinked polyethylene (XLPE) is developed with selective content of dicumyl peroxide (DCP), and the influence of microstructural properties and chemical composition on the mechanical and direct current (DC) dielectric properties are investigated.
0 kommentar(er)
