| As the indispensable equipment in high voltage direct current transmissionsystem, high voltage direct current transmission (HVDC) cable subjects not onlythe rated DC voltage, but also the polarity reversal voltage, operating impulsevoltage and lighting impulse voltage in service. The accessory is the key andweakest part in HVDC cable for its complex compound materials and insulationstructure. In this paper, LSR was modified by doping nano powder to realize theconductivity matching between crosses linked polyethylene (XLPE) insulationand liquid silicone rubber (LSR) insulation under different temperatures andelectric field strength to homogenize the electric field distribution in HVDC cableaccessory.According the preparation process of LSR samples, SiC/LSR and MgO/LSRnanocomposites were prepared with different concentrations. Then, theconductivity and DC breakdown strength of LSR nanocomposites were measuredand compared under different temperatures. The influence of different nanodoping concentration, temperatures and electric field strength of conductivitywere analyzed. Finally, the homogenization of electric field distribution wassimulated with Comsol-Multiphysics in cable accessory, which is composed ofmodified LSR nanocomposites and XLPE.The results show that the nano MgO doping does not has the great influenceon the conductivity of LSR, which couldn’t realize the conductivity matchingwith XLPE to homogenize the electric field distribution. Nevertheless, the nanoSiC doping can improve the conductivity of LSR effectively, which can realizethe conductivity matching between the LSR and XLPE to homogenize the electricfield distribution in cable accessory. Compared with pure LSR, the DCbreakdown strength of MgO/LSR nanocomposites is first falling after rising, andthe DC breakdown strength of SiC/LSR nanocomposites is first rising afterfalling. |
PDF Full Text Request