摘要
对110 k V XLPE电缆绝缘进行100℃和160℃加速热老化实验,通过电声脉冲法(PEA)测量了不同热老化试样的空间电荷分布特性。结果表明:当XLPE试样中有抗氧化剂存在时,氧化反应被抑制,试样中没有出现明显的空间电荷积聚。当抗氧化剂被消耗完毕后,100℃热老化试样内部靠近电极附近出现了明显的异极性电荷积聚,160℃热老化试样内部靠近电极附近出现了大量的同极性电荷积聚,试样中间出现了明显的异极性电荷积聚。热老化试样中的异极性电荷主要来自于热老化产物在电场下电离产生的离子对,而160℃热老化试样内出现的同极性电荷来源于电极的注入。在相同的条件下,未老化试样和100℃热老化试样中并不能观察到明显的同极性电荷的存在,因此,160℃热老化可能会降低XLPE的空间电荷注入阈值场强。
110 kV XLPE cable insulation was conducted accelerated thermal ageing experiments at 100℃ and 160℃ respectively, and the space charge distribution of the aged XLPE samples were tested by pulsed electroacustic method （PEA）. The results show that when there is antioxidant in the XLPE sam- ples, the oxidation reaction would be restrained, and there is no obvious space charge accumulation in the samples. When the antioxidant was consumed completely, there are obvious heteropolar charges accu- mulation near the electrodes of the XLPE samples aged at 100℃, and there are obvious homopolar charges accumulation near the electrodes of the XLPE samples aged at 160℃, but there are obvious het- eropolar charges accumulation in the middle of the XLPE samples. It is found that the heteropolar charges in the aged samples were mainly derived from ionization of polar groups in the XLPE generated during ageing, and the homopolar charges in the samples aged at 160℃ were derived from the injection of electrodes. Under the same condition, there is no obvious homopolar charges accumulation in the unaged samples and samples aged at 100℃. Therefore, the thermal ageing at 160℃ might reduce the space charge injection threshold field.
出处
《绝缘材料》
CAS
北大核心
2017年第11期27-33,共7页
Insulating Materials
