Synthetic furfural analysis for paper insulation ageing diagnosis of transformer

Measuring the furfural content with high performance liquid chromatography is an effective method to trace the aging in oil-immersed transformers. In this paper, current laboratory research and field experiences on furfural analysis in China are introduced. According to the laboratory research, the aging status of cellulosic insulating paper may be determined. Furthermore, combining of the measurements of CO, CO₂ and the furfural content is developed, so that the synthetic ageing diagnosis based on these measured parameters was improved. Besides, the laboratory results are revised for field utilization, taking into account of the differences existing between the laboratory condition and the fields. Rather good agreement has been verified when applying these improved results to many in-service transformers on site.