Abstract

Accurately quantifying gas production during internal faults in transformers is paramount for advancing the digitization and intelligence of electric power equipment. This paper introduces a model grounded in thermodynamics to calculate transformer oil pyrolysis gases, leveraging chemical equilibrium theory to explore temperature-dependent factors such as heat capacity, reaction enthalpy change, and equilibrium constants. By introducing a reaction factor to quantify gas molecule molar fractions, the model establishes a system of chemical equilibrium equations to track gas molecule evolution with temperature. Employing 1 mol of propane as a research subject, our study demonstrates that chain scission reactions predominantly govern thermal cracking reactions of alkanes, with their likelihood increasing with temperature, followed closely by dehydrogenation reactions. The observed evolution of molar fractions aligns well with actual gas generation in oil, offering a reliable method for accurately calculating dissolved gases. This advancement holds promise for enhancing fault diagnosis and maintenance strategies in transformer systems. Further research could explore practical implementations and expand the model's scope to diverse fault scenarios.