The semi-conductive shielding layer plays an important role in the space charge distribution in the insulation layer

and the space charge accumulation in the insulation layer is one of key factors restricting the development of high voltage direct current (HVDC) cables. Allyl chloroacetate (CAAE) grafted ethylene-butyl acrylate copolymer (EBA)/ carbon black (CB) semi-conductive shielding materials is prepared by grafting CAAE onto EBA macromolecular chains through melt grafting. The morphology and structure of the semi-conductive shielding materials are characterized and the volume resistivity is also tested. The space charge distribution characteristics and breakdown field strength of crosslinked polyethylene (XLPE) insulation layer are further tested with the semi-conductive shielding materials as the electrode. Thus

the effects of CAAE content on the electrical properties of the semi-conductive shielding materials

and the space charge distribution characteristics and breakdown field strength of XLPE insulation layer are systematically investigated. The results show that the volume resistivity of CAAE grafted EBA-based semi-conductive shielding materials increases first and then decreases with the increase of CAAE content. Moreover

CAAE grafted semi-conductive shielding can reduce the electric field distortion in XLPE insulation layer. When CAAE content is 1.0phr

the volume resistivity of the grafted semi-conductive shielding materials reaches the minimum. Compared with EBA/CB as the electrode

the maximum electric field distortion factor in XLPE is reduced by 43.2%

69.0%

and 72.4% at 30

40

and 80℃

respectively. The breakdown field strength of XLPE at different temperatures has been significantly improved.