中文摘要：

目前,320 kV交联聚乙烯（crosslinked polyethylene,XLPE）直流电缆是已投运的最高电压等级的柔性直流电缆。XLPE高压直流电缆是柔性直流输电系统的核心设备,将XLPE高压直流电缆绝缘基料国产化具有重要意义。该文测量与评估了多种国内知名厂家生产的绝缘基料的直流击穿电场强度、空间电荷特性与直流电导率,对比国外超净基料、绝缘材料（超净基料＋2%交联剂）对应电性能指标,优选出了两种国产基料,确定了320kV XLPE直流电缆绝缘料用基料国产化的可行性。最后,详细研究了国产基料直流电导率参数,确定了适合于国产基料的电导率拟合函数。

英文摘要：

At present, 320 kV HVDC crosslinked polyethylene （XLPE） cable is the highest voltage level for operational voltage source converter （VSC） HVDC projects. HVDC XLPE cable is a key part of the HVDC transmission system, and developing 320 kV HVDC XLPE cable using China-made base resin is very important. The authors have tested and evaluated DC breakdown strength, space charge behavior and DC conductivity of a number of candidate base resins from Chinese manufacturers, compared corresponding electrical performance with a super clean low density polyethylene （LDPE） material and a super clean LDPE material including 2% crosslinking agents. It has been found that the electrical performances of two candidate base resins are close to or even superior to those of reference materials, which mean that two types of China-made base resin are available for 320kV HVDC XLPE cable from the point of the electrical performance. Finally, DC conductivities of China-made base resins have been studied, and fitting expressions can be obtained.