Study On Main Factors Affecting Performance Of XLPE Insulation

With the sustainable and rapid development of Chinese economy and continuous increasing of urbanization and industrialization,island development has been taken seriously increasingly,the installed capacities of coal-fired,hydraulic and nuclear power stations are continuously increasing,power generation with renewable energies is accelerated and the domestic demand on crosslinked polyethylene(XLPE)insulation high-voltage cable is increasing year by year.Currently,high-voltage cable XLPE insulation materials are mainly monopolized by few transnational companies and most of these materials in China depend on import,which restricts the development of cable industry of China.Therefore,researching the main factors influencing performance of XLPE insulation materials and promoting the substantial improving of performance of such domestic materials do not only have a major scientific significance,but also are expected to obtain remarkable economic and social benefits.In this paper,cross-linking agent absorption method is used to prepare crosslinkable polyethylene materials,research method to determine the optimal diffusion time of cross-linking agent is researched,differential scanning calorimetry is used to research the cross-linking reaction dynamics of polyethylene,relevant parameters are calculated,influence of temperature on XLPE conductivity and dielectric breakdown strength and influence of several antioxidants on XLPE thermo-oxidative aging performance and their emigration performance are surveyed.The research result shows that using nuclear magnetic resonance technology can determine the optimal absorption and diffusion time of cross-linking agent rapidly and accurately;both the type and purity of cross-linking agent will influence the dielectric property of XPLE and cross-linking reaction dynamics parameters;adding antioxidant will increase such parameter values as polyethylene cross-linking reaction order,reaction activation energy and frequency collision factor;in non-sealed environment,the antioxidant in imported crosslinkable polyethylene is easy to emigrate,but after cross-linking,the anti-emigration performance is obviously increased;antioxidant 1035 and imported antioxidant are not easy to emigrate out of XLPE and they can make XLPE have a good anti-thermo-oxidative aging performance.