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 .
The authors would like to thank the personal of Research Chair, ViAHT, at the University of Quebec in Chicoutimi for their availability, and support in material and documentation, the research stay of Dr. Boudraa in Canada. Thanks are also extended to the team and to the head of the chemical research laboratory at the University of Laghouat for the FTIR analyses and their help for the spectroscopy diagram interpretations.
During the visit of Dr Boudraa at UQAC, this research was partially supported by the Natural Sciences and Engineering Research Council of Canada, (NSERC) under grant no. RGPIN-201504403.