Evaluation Method for Insulation Degradation Based on Furfural Content in 35kVField Transformer Oil

摘要

Currently, the evaluation methods of fiber insulation degradation state of power transformer are mostly based on accelerated thermal aging test in laboratory, and this paper is based on the evaluation of furfural content in 35kV field transformer oil. First, samples of the field transformer insulating oil are collected. Then, the insulating oil sample is subjected to an extraction experiment, and the furfural in the insulating oil is extracted by methanol solution. Next, the furfural standard solution is prepared, the methanol extract of the insulating oil and the standard solution are centrifuged and oscillated respectively. After filtration, it is placed in a high-performance liquid chromatograph (HPLC) for injection and measurement. Finally, the furfural content in the insulating oil is obtained. A quantitative equation between furfural and DP is used to evaluate the degree of polymerization (DP) of transformer insulation paper. Combined the field operation with maintenance data, the aging condition of the insulating paper is comprehensively evaluated, and the experimental evaluation results are verified, which provides a reliable reference for the safety operation of field transformers.