植物绝缘油-纸板与矿物油-纸板的加速热老化寿命对比研究

Comparative Study on Accelerated Thermal Ageing of Vegetable Insulating Oil-Paperboard and Mineral Oil-Paperboard

为对比研究植物绝缘油-纸板和矿物油-纸板体系的绝缘老化寿命,先在170℃进行加速热老化对比试验,再根据植物油变压器特有的温升情况,将植物油-纸板体系和矿物油-纸板体系分别在150℃和140℃条件下进行加速老化对比试验,并对经过不同老化试验后的纸板的外观、聚合度及SEM微观结构进行比较分析。结果表明:在170℃下经过1 000 h热老化即等效20年自然老化后,矿物油中纸板结构受到严重破坏,相当于变压器寿命已到晚期,而植物油中纸板结构保持比较完整,聚合度仍在500以上,相当于变压器寿命只到中期;植物绝缘油中纸板体系在150℃条件下的热老化速度比矿物绝缘油-纸体系在140℃条件下的热老化速度慢,进一步说明植物绝缘油-纸板体系比矿物油-纸板体系的寿命更长。

To comparatively study the insulation ageing life of vegetable insulating oil-paperboard and min-eral oil-paperboard, we conducted accelerated thermal ageing experiments at 170 ℃. Then according to the temperature rise of vegetable insulating oil transformer, we conducted accelerated thermal ageing ex-periments at 150℃ for vegetable insulating oil-paperboard and at 140℃ for mineral oil-paperboard. The appearance, polymerization degree, and SEM microstructure of the paperboard after different ageing experi-ments were comparative analyzed. The results show that after the oil-paperboard system is accelerated age-ing for 1 000 h at 170 ℃, that is equivalent to 20 years natural ageing, the structure of paperboard in vegetable insulating oil is damaged severely, which indicates that the lifetime of transformer are in the late stage; while the structure of paperboard in mineral oil maintain complete, and the polymerization de-gree is still above 500, which indicate that the lifetime of transformer are in the middle stage. The accel-erated ageing rate of the vegetable insulating oil-paperboard system at 150℃ is slower than that of the mineral oil-paperboard system, which indicates that the lifetime of the vegetable insulating oil-paperboard is longer than that of the mineral oil-paperboard.