Experimental Improvements Concerning the Thermal Manufacturing Parameters of a new Metal Oxide Varistor Material

Protection of any sensitive piece of electric or electronic equipment against accidental overvoltage occurrence (mostly lightning strokes applied to power networks) is a constant concern for the power electronics domain. The most performant and reliable devices, used as main components to perform this operation, are Metal Oxide Varistors (MOV, or ZnO) surge-arresters. These complex devices are ceramic materials, including different metal oxides, mostly Zinc Oxide (ZnO, around 90% in mass percentage). These electronic devices can work better only if modifying their manufacturing process or by introducing other new additives, which can improve the electrical parameters of the ceramic semi-conductor material, especially on the non-linear dependence between the applied voltage and their response as resulting crossing current. This article is based mostly on an empirical process which can conduct to new semiconductor materials, by modifying some thermal parameters only. This article will describe the influence of the sintering temperature over the main electrical properties, for two newly conceived varsitor materials, only 2 and only 5 main dopants (additives).