Nonlinear Characterization and Simulation of Zinc-Oxide Surge Arresters

Abstract

A combined experimental and numerical procedure to model zinc-oxide varistor based surge arresters is presented. In a series of experiments, measurements on single varistor disks exposed to two millisecond current pulses are taken. Thereafter, the measurement data are used to establish the nonlinear electro-thermal characteristics of the ZnO ceramics under electrical stress. Using this information, an accurate finite element model with coupled thermal and electric fields can be constructed. This approach is applied to calculate the transient voltage and temperature distribution within a complete surge arrester unit.