芳香烃对变压器油的氧化安定性、电气性能、对氧化沉淀的溶解性能和析气性都有极重要的意义。它在变压器油中起天然抗氧剂的作用，但对添加其它抗氧剂的感受性差，芳香烃能改善变压器油的析气性，但介电性能不够好，易与氧化物反应生成沉淀及颜色变深，但芳香烃的溶解性能是好的。芳香烃的结构不同，对变压器油性质的影响也各不相同。
Aromatic hydrocarbons play an important role in the oxidation stability, electrical properties, solubility and gassing properties of transformer oils. It has natural antioxidant in transformer oil, but to add other antioxidants feel bad, aromatic hydrocarbon condensate gas can improve the transformer oil, but the dielectric performance is not good enough, and easy to precipitate and color oxide reaction becomes dark, but the solubility of aromatic hydrocarbon is the best. The structure of aromatic hydrocarbons is different, and their effects on the properties of transformer oils are also different.
(1) 四环芳烃：具有较好的抗氧化性，但易与氧化物反应生成沉淀和颜色，在变压器油中应除去绝大部分这类物质。
(1) aromatic hydrocarbons: they have good oxidation resistance, but easy to react with oxides to produce precipitation and color. Most of these substances should be removed in transformer oil.
(2) 三环芳烃：是很好的天然抗氧剂，溶剂精制对它选择性不大，而酸碱精制易除去它，含酚型抗氧剂不能阻止它的氧化，并且氧化后易生成沉淀。美国六十年代加工工艺除去大部分这类烃。
(2) tricyclic aromatic hydrocarbon: it is a good natural antioxidant, solvent refining is not very selective to it, and acid base refining is easy to remove it. Phenol containing antioxidant can not prevent its oxidation, and easy to precipitate after oxidation. The United States produced most of these hydrocarbons in 60s.
(3) 双环芳烃：与饱和烃在一起时能起抗氧化的作用，但有单环芳烃存在时，此作用消失，对抗氧剂的感受性也不好，但双环芳烃有利于改善和提高变压器油抗析气性能。
(3): aromatics and saturated hydrocarbon can have antioxidant effect together, but there are single aromatic ring, this effect disappeared, susceptibility to the antioxidant is not good, but PAHs help improve and enhance the anti gassing property of transformer oil.
