Study on the formation of microvaristor chains in composite varistors and their electrical characteristics

The composite varistor of epoxy resin and microvaristor has nonlinear voltage-current characteristics owing to microvaristor chains, which work as current paths, formed by applying an electric field during curing process. In this type of composite varistor, voltage-current characteristics and surge absorption capability are typical basic performance and strongly influenced by the chain formation and intrinsic characteristics of microvaristors. This paper reports the influence of gravity and electric field on the formation of microvaristor chains in epoxy resin and voltage-current characteristics and surge absorption capability of one microvaristor itself.