Nonlinear electrical material for high and medium voltage applications

Abstract

The invention relates to a nonlinear electrical material with improved microvaristor filler (), to devices and electrical apparatuses comprising such nonlinear electrical material and to a production method thereof. According to invention, the filler () comprises larger spherical particles () and smaller irregular particles () that are arranged interstitially and provide non-point-like and/or multiple contact areas () owing to their irregular outer shape comprising edges and faces. Embodiments, among other things, relate to: spherical particles () being calcinated and broken-up to retain their original shape; irregular, spikly shaped, particles () obtained by calcinating or sintering and crushing or fracturing granules or blocks; and addition of a third filler fraction. Advantages, among others, are: higher filler contents, more and more durable inter-particle contacts (), enlarged effective micro-contact area, and improved electrical performance of the nonlinear electrical material.