二苄基二硫含量对矿物绝缘油老化特性的影响

为研究油中二苄基二硫(DBDS)含量对矿物绝缘油老化特性的影响,分别制备了DBDS含量为0%、0.05%、0.1%的绝缘油样品,与绝缘纸复合后在130℃下进行加速热老化试验,定期取油样测试离子迁移率、介质损耗、电导率、酸值、油中铜含量等性能参数并进行分析。结果表明:DBDS能加速绝缘油老化,DBDS含量越高,绝缘油老化越严重;在老化过程中,离子迁移率活化能呈现先减小后增大的趋势,即存在一个拐点,这是由不同老化时期油中载流子种类及含量变化导致,DBDS含量越高,绝缘油老化越严重,拐点时间越靠前;绝缘油电导率和油中离子浓度随老化时间变化规律一致,离子浓度增大是导致老化后绝缘油电导率增大的主要原因。

Influence of Dibenzyl Disulfide Content on Aging Characteristic of Insulation Oil

To investigate the influence of dibenzyl disulfide (DBDS) content in oil on the aging characteristics of insulation oil, oil samples with different DBDS concentrations (0%, 0.05% and 0.1%) were made. Together with insulation paper, these oil samples were used to perform thermal aging experiments under 130℃. The properties of ion mobility, dielectric loss, conductivity, acid value and copper content were analyzed. Experimental results showed that DBDS contributed to accelerating the aging of insulating oil, that is, the higher DBDS content in oil, more serious aging degree of insulation oil will be. In addition, the activation energy of oil increased and then decreased in the whole process of aging. An inflection point appeared. The variations of the carrier types and contents in oil at different aging periods were regarded as the reasons to this phenomenon. The appearance time of aforementioned inflection point could be shifted to an earlier date under the effect of DBDS. More DBDS content in oil, this phenomenon was more obvious. Furthermore, the conductivity and ion concentration in the oil changed with aging time, but their variations presented the same tendency. The increase of ion concentration in the oil was the main reason leading to the increase of the conductivity of insulation oil.