A new method, which involves the addition of alkaline Al2O3 (3 wt%) and activated clay (5 wt%) as adsorbents for homogeneous synthetic trimethylolpropane triesters (TME), is reported here to not only improve electrical properties but also to shed light on future volume production. The results show that the acid value and the dielectric loss of TME oil is successfully reduced and meets IEC 61099. The viscosity of TME approaches that of mineral oil (MO) for transformers. In addition, TME oil with antioxidants exhibits fairly good oxidation stability that is evidenced by a notably high oxidation onset temperature of 226°C, which is 39 K and 14 K higher than that of commercial natural ester oil (NEO) (187°C) and MO (212°C), respectively. Furthermore, compared with the AC breakdown voltage (Vb) of NEO (65.3 kV) and MO (70.4 kV), the TME oil has a higher Vb=73.2 kV. Besides, the positive lightning impulse (LI) Vb and streamer behavior of TME at small gaps are comparable to those of MO and NEO. However, the negative LI Vb of TME and NEO are significantly lower than that of MO owing to the combined field variation towards the plane electrode which will facilitate the propagation of the streamer. Therefore, additives without oxygen, fluorine and chlorine should be given priority when they are used to improve the properties of insulation oil.

中文翻译：

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均相合成三羟甲基丙烷三酯绝缘油的击穿和流光行为


本文报道了一种新方法，其中涉及添加碱性 Al2O3 (3 wt%) 和活性粘土 (5 wt%) 作为均相合成三羟甲基丙烷三酯 (TME) 的吸附剂，不仅可以提高电性能，还可以揭示未来量产。结果表明，TME油的酸值和介电损耗成功降低，符合IEC 61099标准。TME的粘度接近变压器用矿物油（MO）的粘度。此外，含有抗氧化剂的 TME 油表现出相当好的氧化稳定性，氧化起始温度高达 226°C，比商用天然酯油 (NEO) (187°C) 高 39 K 和 14 K和MO (212°C)，分别。此外，与NEO（65.3 kV）和MO（70.4 kV）的交流击穿电压（Vb）相比，TME油具有更高的Vb=73.2 kV。此外，小间隙下TME的正雷电冲击（LI）Vb和流光行为与MO和NEO相当。然而，由于朝向平面电极的组合场变化有利于流光的传播，TME和NEO的负LI Vb明显低于MO。因此，在使用改善绝缘油性能时应优先选用不含氧、氟、氯的添加剂。