Hydrodynamic Modeling for Discharge Analysis in a Dielectric Medium with the Finite Element Method under Lightning Impulse

Abstract

-The response of lightning impulse voltage was explored in dielectric liquids employing hydrodynamic modeling with three charge carriers using the finite element method. To understand the physical behavior of discharge phenomena in dielectric liquids, the response of step voltage has been extensively studied recently using numerical techniques. That of lightning impulse voltage, however, has rarely been investigated in technical literature. Therefore, in this paper, we tested impulse response with a tip-sphere electrode which is explained in IEC standard #60897 in detail. Electric fielddependent molecular ionization is a common term for the breakdown process, so two ionization factors were tested and compared for selecting a suitable coefficient with the lightning impulse voltage. To stabilize our numerical setup, the artificial diffusion technique was adopted, and finer mesh segmentation was generated along with the axial axis. We found that the velocity from the numerical result agrees with that from the experimental result on lightning impulse breakdown testing in the literature.

Electrohydrodynamic Analysis of Dielectric Guide Flow Due to Surface Charge Density Effects in Breakdown Region

“…Electrical insulation is the most important consideration in electrical power devices such as power transformers, vacuum interrupters, circuit breakers, and transmission lines [1][2][3][4][5][6][7][8]. In power electrical systems, most failures of the insulation systems are associated with the breakdown of solid insulators [9].…”