Experimental Study on Arc Discharge Pressure and Gas Production Characteristics in Transformer Oil

Oil-immersed transformers are critical components in electric power system. Under high-energy discharge conditions, mineral oil has a propensity to generate substantial quantities of flammable gases, potentially leading to catastrophic explosions in oil-filled equipment. An in-depth investigation of the arc discharge characteristics in oil is essential to establish a theoretical foundation for enhancing the fire prevention and explosion resistance capabilities of oil-filled equipment. To simulate arc faults within transformers, an oil immersion arc discharge testing platform was constructed. Utilizing devices such as voltage probes, Rogowski coils, and high-frequency pressure sensors, key parameters including voltage, current, pressure, and gas generation were measured. Arc discharge tests were conducted, and data for various parameters were acquired. The experimental results exhibited consistency with established theories. The test achieved an energy level of 45 kJ. The recorded voltage waveform exhibited a rectangular shape with an amplitude of approximately 200 V. The pressure exceeded 650 kPa, and the gas production volume was approximately 4.1 L, with a gas production rate of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$90 \text{ml} / \text{kJ}$</tex>. The composition of the gases produced was determined to be 76.7 % hydrogen and 6.5 % acetylene, along with other hydrocarbon compounds. These findings corroborate the existing theoretical understanding of arc discharge phenomena in oil-immersed transformers.