FTIR and FDS assessment of mineral oil under low electrical discharge

Abstract

Transformers are crucial elements in the chain of transmission of electrical energy. The diagnosis of this important element in the electrical network is necessary for the continuity of energy distribution and to avoid the economic and environmental damage that may occur. Electrical and thermal stress or chemical contamination due to which insulation oil inside the transformer is highly degraded and can cause failures or reduce component life. Among the most common stresses that can lead to degradation of insulating oil in transformers is partial discharge. The present work aims to understand the influence of low energy electrical discharge in mineral oil by using two spectroscopic methods: FTIR spectroscopy and a frequency domain spectroscopy. An electrical fault has been created by continuous discharge of 10 kV for diffirent ageing time . According to frequency domain spectroscopy’s results, the amount of charges carriers and moisiture increases with the aging time and influence the conduction phenomena which in turn increases the dissipation factor. This result is also confirmed by the FTIR results. The correlation between this two methods can help to butter diagnostic .

Keywords

• diagnostic
• infrared spectroscopy
• mineral oil
• low electrical discharge
• dielectric spectroscopy