Analysis of Transformer Tank Deformation and Rupture, Part 2: Checking of Ability of Transformer Tank Withstand Internal Short-Circuit Arc Fault

In this paper, by comparing the transmission capacity of different voltage levels and the requirements of system power supply configuration, it is discussed that the risk of oil tank deformation and rupture increases when facing potential internal short-circuit arc fault, which puts forward higher requirements for large oil-filled transformer equipment oil tank's ability to withstand internal short-circuit arc fault. Through the calculation of single-phase short-circuit current, analysis of instantaneous short-circuit current, and the recommended value (100ms) for short-circuit duration evaluation, a statistical-based method for checking and evaluating the transformer oil tank's ability to withstand internal short-circuit arc faults is introduced. Finally, based on the idea of evaluation method, measures to reduce the risk of oil tank deformation and rupture are discussed including reducing the system short-circuit capacity faced by the equipment and selecting reasonable tank structures and volumes, which provides a framework for analyzing and evaluating the transformer oil tank's ability to withstand internal short-circuit arc faults.