Modeling and Analysis of Metal Oxide Surge Arrester Configurations

Abstract

It is essential to protect electrical power system apparatus from lightning impulses and switching surges for reliable operation and to avoid possible damage to the electrical power equipment. In the present scenario, metal-oxide surge arresters with polymeric outer casing have come up with high energy absorption capability to protect the equipment from high voltage surges. Metal-oxide surge arrester consists of a column of zinc-oxide blocks which offers a highly non-linear V-I characteristic to ground the surge energy safely.

The project work focuses on the modeling and analysis of polymeric housed metal-oxide surge arrester assembly and to establish its behavior for various configurations and possible non-uniformity in the bulk of material. The aim is to determine voltage, heat distribution and structural stability under steady-state and transient conditions. To achieve this, it has been modeled and analyzed using a Finite Element Technique based simulation software package.

The treatise encompasses electro-thermal and structural analysis of metal-oxide surge arrester assembly for a single module under voltage impulse and short-circuit test as prescribed in international standards. In the submitted report, the zinc-oxide block has been examined for residual voltage test to have the idea of its thermal capability. The surge arrester assembly has also been analyzed for a parallel configuration. In addition to it, its behavior has been observed by introducing a non-uniformity in bulk of one of the zinc-oxide blocks. The results that have been observed are voltage and current distribution in case of electrical analysis, temperature profile during transient thermal analysis and for structural domain, total deformation of the object, equivalent stress-strain and thermal strains. After each and every test, the stability of the structure has been predicted in order to evaluate its failure.

As a result of the work, necessary design modifications have been suggested in order to improve its performance so that it can serve its duty well under all kind of operating conditions with out a catastrophic destruction.