变压器油氧化安定性快速评定方法的建立及应用

ESTABLISHMENT OF RAPID EVALUATION METHOD FOR OXIDATION STABILITY OF TRANSFORMER OILS

介绍了国内外评定变压器油氧化安定性的试验方法。选择国内市场常用的变压器油样品,对经典的变压器油氧化安定性评定方法 NBSHT 0811与ASTM D2112旋转氧弹法进行对比研究。研究结果表明,现用的ASTM D2112旋转氧弹法(140℃,620 kPa氧气压力)的评价结果与NBSHT 0811方法 (120℃,500 h)的一致性不好,在过高的试验温度下评定变压器油氧化安定性会导致错误的评价结果。在旋转氧弹法测试原理的基础上,提高氧弹内最初的氧气压力到1 500 kPa,降低温度到120℃,以氧气压力下降速率最快的时间点作为氧化终点,形成了一种新的快速评价方法。采用该方法评定的结果与经典氧化试验法评定结果的一致性好,且该方法的区分性和重复性亦较好,可以作为变压器油氧化安定性评定的前期辅助方法。

The transformer oil oxidation stability was tested by two methods of classical NB/SH/T＆amp;nbsp;0811 and ASTM D2112 Rotating Bomb Oxidation,different results were observed. The inconsistency is caused by high temperature （140 ℃）and lower oxygen pressure （620 kPa）of the RBOT method. At the optimized conditions of 120 ℃ and 1 500 kPa,and taking the time at which the quick reduction of oxygen pressure occurs as the end point,the consistency of the two methods is obtained. Based on these experiments,an easy and reliable method as early assisted method for evaluating oxidation stability of transformer oil is established with best resolving power and repeatability.