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Electric tree branches are a typical defect in cross-linked polyethylene high-voltage DC cables, and their initiation and growth will ultimately lead to cable breakdown. And the physical and chemical properties of XLPE will have a certain effect on the growth of DC branches. In this paper, XLPE for AC and DC cable were used to prepare pressed sample pieces, and XLPE samples were obtained from finished AC cables. The physicochemical properties of different XLPE were studied by means of DSC, XRD, GPC. And through electrical tree growth experimental system, the DC tree growth process and partial discharge characteristics of different XLPE needle plate samples were compared and analyzed. The results show that among the three materials, XLPE for DC has the smallest crystallinity, larger grain size, larger relative molecular weight of the polymer, and better resistance to electrical tree branches. And the finished AC cable has higher crystallinity, smaller wafer thickness and close to the polymer relative molecular mass of XLPE for AC, with average resistance to electrical tree branches.
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