Power transformers are one of the most dangerous pieces of electrical equipment because of the large quantity of oil they contain, which is in direct contact with high voltage elements. Under such circumstances, low impedance faults that result in arcing can appear in transformer tanks once the oil loses its dielectric properties. Oil is then vaporized and the generated gas is pressurized because the liquid inertia prevents its expansion. The pressure difference between the gas bubbles and the surrounding liquid oil generates a dynamic pressure peak, which propagates and interacts with the tank and builds up static pressure. Then, the static pressure rises, leading to tank explosion and possible fire.
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