中文摘要：

为了研究脱气处理对XLPE及其复合介质中空间电荷的影响，采用螯合剂与线性低密度聚乙烯接枝马来酸酐（MAH）作为填料，与XLPE共混制成掺杂浓度为0．5wt％的MAH／XLPE复合介质，并用电声脉冲法（PEA）测量了XLPE及MAH／XLPE复合介质在不同脱气时间下的空间电荷分布。通过实验发现，增加脱气处理的时间可以减少所制各样品内交联副产物的残余量。此外，空间电荷注入阚值随着脱气时间的增加而升高。从不同短路时间下的空间电荷分布可以看出，在正极性电场下，交联副产物对外主要表现为负电荷。从XLPE与MAH／XLPE复合介质中的空间电荷分布还可以发现，MAH的加入，提高了束缚杂质离子的缺陷的能级，抑制了杂质离子在介质中的迁移，并使MAH／XLPE复合介质中空间电荷分布更均匀。同时，还发现脱气时间的长短与向XLPE中添加填料后能否有效地改善XLPE中空间电荷的分布有着密切的关系。经过较长时间的脱气处理后，掺杂少量的螯合剂MAH也可以有效改善XLPE复合介质内空间电荷的分布。

英文摘要：

In order to investigate the effect of de-gassing on the space charge in XLPE and its composite, we added chelating agent and LLDPE grafted maleic anhydride （MAH） to XLPE and by compounding produced a MAH/XLPE composite with dopant concentration of 0.5%. The space charge distribution in XLPE and MAH/XLPE composite after different degassing time was measured by the pulsed electro-acoustic （PEA） method. It was found by experiment that the amount of crosslinking by-products would decrease with degassing time increased. Besides, the space charge injection threshold would be raised with degassing time increased. It was found from the space charge distribution with different short-circuiting time that the crosslinking by-products took mainly the form of negative charges under positive electric field. It was also found from the space charge distribution in XLPE and MAH/XLPE composite that the addition of MAH increased the energy level to limit impurity defects and prohibited the migration of impurities in dielectrics, making the space charge distribution in XLPE and MAH/XLPE composite more uniform. Furthermore, it was found that the degassing time was closely related to the capability of additives to XLPE to improve space charge distribution. After long time degassing, even small amount of chelating agent MAN additives can effectively improve the space charge distribution in XLPE composites.