I. Introduction
The power transformers are the essential components of power transmission systems, and their operational health directly influences the reliability and stability of electricity supply [1]. The transformer oil exhibits superior insulation and heat dissipation properties, effectively preventing internal metal components from corrosion and oxidation. Consequently, it is widely utilized in power transformers to enhance performance and extend service life. Among various faults, penetrating arc discharge poses a significant threat to the integrity of the insulation structure within transformers [2], [3]. The occurrence of an arc discharge leads to rapid decomposition of the insulation materials, generating substantial gas in a short time frame, which results in a swift pressure increase within the oil tank [4], [5]. Additionally, a considerable volume of oil rapidly flows back into the transformer conservator from the tank. The oil flow velocity serves as a critical parameter indicative of arc fault severity [6]. Therefore, precise monitoring of oil flow velocity is crucial for effectively mitigating deflagration-related arc discharges.