基于响应曲面法的变压器油T501电化学测试条件优化

Optimization of electrochemical test conditions for transformer oil T501 based on response surface method

T501作为广泛应用于变压器油中的抗氧化剂,它的加入能显著延缓油的氧化速度,从而延长油品的寿命,但是添加过量的抗氧化剂,又会影响油的电气性能,因此精确测定T501含量很重要。本文主要通过响应曲面法(RSM)和方波伏安法(SWV)研究了在采用三电极体系和确定电极材料为石墨电极的前提下,电解质种类及浓度、最佳有机溶剂种类及含水量等对T501含量测试的影响,进而筛选出最适宜的测试条件。结果表明:最佳工作电极直径为6 mm,最佳电解质为KOH,浓度为0.18 mol/L,最佳有机溶剂为乙醇,含水量1%;在该条件下,变压器油中T501质量分数与峰电流大小Ip线性关系良好,回收率为96.60%~102.10%;使用优化后的电解质溶液对运行变压器油中T501含量进行检测,结果与GB/T 7602.2液相色谱法结果具有一致性。

T501 is the most common antioxidant widely used in transformer oils.Its addition can significantly slow the oxidation rate of the oil,thereby the service life of oil would be prolonged.However,adding excessive antioxidants will affect the electrical performance of the oil,so it is important to accurately determine the content of T501.This article mainly studies the influence of electrolyte type on the T501 test by response surface method(RSM)and square wave voltammetry(SWV),on the premise of using a three-electrode system and the electrode material has been determined.Then,the most suitable test conditions are chosen.The results show that,the best diameter of the working electrode is 6 mm,the best electrolyte is KOH with a concentration of 0.18 mol/L,and the best organic solvent is ethanol with a water content of 1%.Under this condition,the T501 mass fraction in the transformer oil has a good linear relationship with the peak current Ip,and the standard addition recovery rate is 96.60%~102.20%.The optimized electrolyte solution was used to detect the T501 content in the operating transformer oil,and the measurement results were consistent with those acquired by GB/T 7602.2 liquid chromatography.