Propagation characteristics of pressure waves caused by arc discharge in oil under impulse voltage

Arc faults within the transformers can generate sudden pressure surges, constituting significant hazards that may precipitate oil tank explosions and severely compromise power system stability. Conventional power−frequency arc discharge experiments encounter limitations in isolating pressure wave characteristics due to persistent gas generation and arc reignition. To circumvent these challenges, an oil-immersed impulse voltage discharge platform was conceived and engineered to investigate pressure wave propagation dynamics. A pressure numerical simulation model and theoretical model of oil−solid interface reflection and refraction were subsequently established to elucidate the pressure propagation mechanism. The experimental and simulation results show that the pressure wave generated by pulsed arc discharge in oil propagates radially in the form of spherical waves. Due to the viscous loss and wave front expansion of transformer oil, the peak pressure decays exponentially with distance, with a decay coefficient β = 1.15. When pressure waves encounter metal obstacles inside transformer oil, there are two propagation paths: direct transmission through and multiple reflections through, and a mode transformation of pressure waves occurs at the oil−solid interface, mainly propagating through obstacles in the form of transverse waves. This work quantitatively delineates the energy pressure wave coupling, propagation dynamics, and attenuation mechanisms, providing critical insights for assessing and mitigating arc fault-induced transformer explosion risks.