TiO_2纳米粒子对高水分变压器油中电荷输运的影响

Effect of TiO_2 Nanoparticles on Charge Transportation of Transformer Oil with High Moisture Content

水分是导致运行中变压器油绝缘性能下降的重要因素之一。为了提高高水分含量下变压器油的绝缘性能,本文利用半导体TiO2纳米粒子对变压器油进行改性研究。测量了不同水分含量下改性前后变压器油的工频击穿和局部放电特性。发现当变压器油中含水量较高时,半导体TiO2纳米粒子不仅可以使变压器油的工频击穿电压提高至改性前的2倍以上,而且可以有效抑制油中局部放电现象。利用电声脉冲(PEA)对变压器油中电荷累积和消散特性进行了测量研究,结果发现:TiO2纳米粒子能够提高高水分变压器油中电荷的消散速率,一定程度上抑制了水分对变压器油中电场的畸变,从而提高了变压器油的绝缘性能。

Moisture plays a key role in determining the insulating properties of transformer oil in service. In order to improve the insulating properties of transformer oil with high moisture content, TiO2 semiconducting nanoparticle was used to modify the transformer oil. Breakdown voltage and partial discharge(PD) characteristics of both oil samples before and after modification were measured with different moisture content. It was found that TiO2 nanoparticles can increase AC breakdown voltage of nanofluids up to 2 times compared with pure oil with high moisture content. In addition, the PD characteristic of the nanofluids was also dramatically improved. Charge accumulation and decay characteristics in pure oil and nanofluids were measured by pulse electroacoustic technique(PEA). It reveals that with high moisture content the nanofluids have higher charge decay rate and more uniform internal electric fields resulting in the better dielectric properties.