Transformer oil is the main insulation and cooling medium of oil immersed transformer. Its electrical strength and chemical composition directly affect the function of transformer. If the oil contains a small amount of moisture and impurities, it will reduce the insulation strength; and if the oil and oxygen touch, it is easy to oxidize and degenerate under high temperature. Therefore, transformer oil filtration should be carried out during transformer installation.

变压器油是油浸变压器的主要绝缘、冷却介质，其电气强度和化学成分的好坏，直接影响变压器的功能。假如油中含有少量水分和杂质，就会使绝缘强度下降；且油与氧气触摸，在高温下容易氧化而蜕变。因而，变压器装置时要进行变压器油过滤。

Transformer oil is the main insulation and cooling medium of oil immersed transformer. Its electrical strength and chemical composition directly affect the function of transformer. If the oil contains a small amount of moisture and impurities, it will reduce the insulation strength; and if the oil and oxygen touch, it is easy to oxidize and degenerate under high temperature. Therefore, transformer oil filtration should be carried out during transformer installation.

防止油质变坏而致使的安全运转受到的影响，应对正常运转的配电定时采油样进行化验剖析，根据剖析的结果对油进行相关处理。配电运转油化学监督的检验周期规定为至少3年一次。

In order to prevent the impact on the safe operation caused by the deterioration of oil quality, the regular oil production samples of the normal operation of power distribution shall be tested and analyzed, and the oil shall be treated according to the analysis results. The inspection cycle of distribution and operation oil chemical supervision is stipulated to be at least once every 3 years.

酸值

acid value

酸值是表示油中含有酸性物质的数量，中和1g油中的酸性物质所需的氢氧化钾的毫克数称为酸值。酸值包括油中所含有机酸和无机酸，但在大多数情况下，油中不含无机酸。因而，油酸值实际上代表油中有机酸的含量。新油所含有机酸主要为环浣酸。在储存和使用过程中，油因氧化而生成的有机酸为脂肪酸。酸值对于新油来说是精制程度的一种标志，对于运转油来说，则是油质老化程度的一种标志，是断定油品是否能持续使用的重要指标之一。

Acid value refers to the amount of acid contained in the oil, and the milligram of potassium hydroxide required to neutralize the acid in 1g oil is called acid value. Acid value includes organic acid and inorganic acid in the oil, but in most cases, the oil does not contain inorganic acid. Therefore, the oleic acid value actually represents the content of organic acids in the oil. The organic acid in the new oil is mainly cyclohuanic acid. In the process of storage and use, the organic acid produced by oil oxidation is fatty acid. Acid value is a sign of refining degree for new oil, a sign of aging degree for running oil, and an important indicator to determine whether the oil can be used continuously.

水溶性酸

Water soluble acid

其超极限值为小于4.2。超出极限值的或许原因有2种：油质老化;油被污染。对水溶性酸超出极限值可采纳如下对策：增加实验次数，并与酸值比较查明原因。进行油的再生处理，若经济合理可做换油处理。

Its exceeding limit value is less than 4.2. There are two possible reasons for exceeding the limit value: oil aging and oil pollution. The following countermeasures can be adopted for the water-soluble acid exceeding the limit value: increasing the number of experiments and comparing with the acid value to find out the reasons. Carry out oil regeneration treatment. If it is economical and reasonable, oil can be changed.

击穿电压

breakdown voltage

其超极限值为小于20KV。超出极限值的或许原因有2种：油中含水量过大;油中有杂质颗粒污染。对击穿电压超出极限值可采纳如下对策：查明原因，进行真空滤油处理、板框压力式滤油机处理或更换新油。一般选用ZJB真空滤油处理后油的击穿电压要求大于50KV。

Its exceeding limit value is less than 20kV. There are two possible reasons for exceeding the limit value: excessive water content in the oil; impurity particle pollution in the oil. The following countermeasures can be adopted for the breakdown voltage exceeding the limit value: find out the cause, conduct vacuum oil filtering treatment, plate and frame pressure oil filter treatment or replace with new oil. Generally, the breakdown voltage of oil after zjb vacuum oil filtering treatment is required to be greater than 50kV.

闪点

flash point

其超极限值为小于130℃。或者比前次实验值下降5℃。超出极限值的或许原因有2种：设备存在局部过热毛病;补错了油。对闪点超出极限值可采纳如下对策：查明原因，消除毛病;进行真空滤油机脱气处理，或进行换油处理。

Its exceeding limit value is less than 130 ℃. Or 5 ℃ lower than the previous experiment. There are two possible reasons for exceeding the limit value: local overheating of the equipment; wrong oil filling. The following countermeasures can be adopted for the flash point exceeding the limit value: find out the cause and eliminate the fault; carry out degassing treatment of vacuum oil filter or oil change treatment.

外状

Exomorphic

假如外观目测油不透明，有可见杂质或悬浮物。或油色太深，则为油外观反常。外观反常的或许原因有：油中含有水分、纤维、碳黑及其它固体物。对外观反常的油应采纳以下对策：若油模糊不清、浑浊发白，标明油中含有水分，应查看含水量。若发现油中含有碳颗粒，油色发黑，甚至有焦臭味，则或许是内部存在有电弧或局部放电毛病，应与其它实验结合，调查原因，排除毛病。若油色发暗，并且油的颜色有显着改变，则应注意油的老化是否加速，可结合油的酸值实验剖析，或加强油的运转温度的监控。

If the appearance of the oil is not transparent, there are visible impurities or suspended substances. Or if the oil color is too deep, the oil appearance is abnormal. The possible causes of abnormal appearance are: water, fiber, carbon black and other solid substances in the oil. The following measures should be taken for the oil with abnormal appearance: if the oil is unclear, turbid and white, it should be indicated that there is water in the oil, and the water content should be checked. If it is found that there are carbon particles in the oil, the color of the oil is black, and even there is a smell of scorching, it may be that there is an arc or partial discharge fault in the oil, which should be combined with other experiments to investigate the cause and eliminate the fault. If the color of the oil is dark and the color of the oil changes significantly, it is necessary to pay attention to whether the aging of the oil is accelerated. It can be combined with the analysis of the acid value experiment of the oil, or strengthen the monitoring of the operating temperature of the oil.