Removal of Dibenzyl Disulfide (DBDS) by Polyethylene Glycol Sodium and Its Effects on Mineral Insulating Oil

Dong Ding,Lijun Yang,Wei Li,Bangfei Deng,Haibing Zhang,Yuxin He,Zhaoguo Wu

doi:10.1109/access.2019.2937393

Dong Ding, Lijun Yang + Show 5 more

Open Access

https://doi.org/10.1109/access.2019.2937393

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Abstract

Dibenzyl disulfide (DBDS) is the major corrosive sulfur compound in mineral insulating oils, which will corrode the copper wires of windings in the oil-immersed power transformers and reactors and eventually cause operation failures. This paper studies the method to eliminate DBDS in insulation oils using the Polyethylene Glycol Sodium (Na-PEG) reagent. The preparation method of the Na-PEG reagent from NaOH and polyethylene glycol 400 is studied in the laboratory. The effect of the Na-PEG reagent dosage and reaction temperature on eliminating DBDS in insulating oils is studied, and a treatment process is recommended. An automatic processing device to remove DBDS from the transformer oil is developed, and the short-term electrical properties and long-term thermal stability of the insulating oil after the Na-PEG reagent treatment are tested. The results show that the Na-PEG reagent can efficiently eliminate DBDS in the insulating oil (the DBDS concentration decreases from 448 mg/kg to less than 5 mg/kg (undetectable) within 1 hour) and will not significantly negatively affect the oil properties such as the breakdown strength at the power frequency, dissipation factor or acidity. A preliminary exploration of the reaction mechanism is explored.

Highlights

Oil-immersed power transformers and reactors are the major equipment in power systems, and severe transformer or reactor failures may cause tremendous economic loss [1]
The Na-PEG preparation method was explored, and contrast experiments were performed to determine the suitable dosage of Na-PEG and the proper reaction temperature to remove Dibenzyl Disulfide (DBDS) in the oil
First, the insulating oil with DBDS reacted with the Na-PEG reagent in the reaction unit x; the oil was kept stable for layering

Summary

Introduction

Oil-immersed power transformers and reactors are the major equipment in power systems, and severe transformer or reactor failures may cause tremendous economic loss [1]. The Na-PEG preparation method was explored, and contrast experiments were performed to determine the suitable dosage of Na-PEG and the proper reaction temperature to remove DBDS in the oil.

Results

Conclusion