Study on Nonlinear Dielectric Properties of Micro Silica

Inorganic insulating powder can potentially be used in nuclear power plant cables, fire-resistant and so on due to its high heat resistance radiation resistance. It is of great academic engineering value study the dielectric properties inorganic powder. In this paper, we aim nonlinear via measurement time-domain polarization current spectrum under application a DC electric field. Three kinds silica powders are measured by system with adjustable pressure. The effects shape, particle size, packing pressure temperature dependence relaxation electrical conductivity applied field studied. experimental results show that relationship between presents two different characteristics, i.e., field-induced enhancement weakening. conductance shows an increase temperature. That is, increases or decreases insulation regarded as composite, which composed particles air gaps. interface gaps contributes lot phenomena (including weakening characteristic decrease increasing temperature) explained simplified mechanism.