Estimation of the structure non-homogeneity of multicomponent insulation of electrical machines using digital measuring methods

Abstract

Preliminary studies show that multichannel pulse-height analysis of partial discharges is useful for evaluating the state of the complex dielectric material of the glass fabric/mica paper/resin type, employed for high voltage insulation of electrical machines. Charge distributions of partial discharges characterising the proper samples and those overheated during pressing differ substantially. All the selected parameters characterising partial discharges, determined on the basis of charge distributions, such as the total charge Q, the maximum charge Q/sub max/, and the total charge of the last distribution ranges (e.g. charges Q/sub >75%/ or Q/sub >50%/) are of much greater values for the samples overheated during pressing than for the samples properly pressed.