Update of a design pressure equation for power transformers under high-energy arcing faults

High-energy arcing faults in liquid-immersed transformers and reactors can cause rapid pressure rises, leading to tank rupture and severe consequences. Traditional design guidance relies on a primary design equation that estimates a peak pressure based on fault energy, tank flexibility, gas generation from oil decomposition, and a dynamic amplification factor. This equation assumes isothermal gas expansion, constant tank flexibility, and incompressible oil.