Numerical and experimental validation of discharge current with generalized energy method and integral ohm's law in transformer oil

The discharge currents were evaluated and validated using the generalized energy method and the integral Ohm's law combined with the recently developed discharge analysis technique for dielectric liquid media, such as transformer oil. The terminal current in voltage-driven systems was found to play an essential role in characterizing the pattern of electric discharge, such as corona, breakdown, etc. Until now, the generalized energy method and integral Ohm's law were normally adopted to evaluate this terminal current, but no experimental validation was reported and no test was performed in a dielectric liquid media. The generalized energy method can be derived directly using Poynting's theorem and is well suited for the finite element method. As an alternative approach, the integral Ohm's law can be applied to multiport systems. To confirm the numerical results, an experimental setup was proposed with a multiport system composed of a tip and separated conducting ring shells. The numerical results were compared with those from experiments, which would be the first trial in a dielectric liquid with a multiport system. The calculated current profile was similar to that from the experimental result, but the breakdown voltage from the calculated results was relatively high.