Space charge measurements on multi-dielectrics by means of the pulsed electroacoustic method

Abstract

The Pulsed Electroacoustic (PEA) method is now widely accepted as one of the most simple and effective techniques for the measurement of the dynamic space charge distribution in solid dielectrics. Recently, the PEA method has been applied also to laminar test objects composed of two or more layers of different dielectrics (multidielectrics). However, when a multi-dielectric is tested by means of the PEA method, the different acoustic and electric properties of the materials affect the detected space charge signal. In this paper, the principle of the PEA technique is reviewed in case the test object is a multi-dielectric. The generation, transmission and reflection of electrically-induced acoustic waves are described. Based on the proposed approach, results of PEA measurements performed on various kinds of multi-dielectrics are presented and discussed.

Dielectric Interfaces in DC Constructions: Space Charge and Polarization Phenomena

“…Space charge profiles were obtained by processing the acquired raw acoustic signal. Not only deconvolution techniques [5] were used, but also the procedures developed in [6] were adopted for taking into account the fact that the test objects considered in this work are acoustically and electrically heterogeneous. Measurements were performed at different values of the applied field, in the range 5 -20 kV/mm.…”

Maxwell–Wagner Effect in Multi-Layered Dielectrics: Interfacial Charge Measurement and Modelling

“…Case studies for inhomogeneous dielectrics are treated for the various techniques by Holé et al [18]. So far, most of the works on space charge measurements in multi-dielectrics have been achieved by the PEA method [10,14,19]. The application of acoustic methods to recover the charge distribution requires the treatment of acoustic wave propagation and transmission into the various layers.…”

“…The application of acoustic methods to recover the charge distribution requires the treatment of acoustic wave propagation and transmission into the various layers. A thorough analysis of the problem for the PEA method has been achieved by Bodega et al [10]; such an analysis has been reconsidered recently [20].…”

“…To alleviate this issue, specific measurement techniques can be implemented for field distribution estimation through space charge density distribution, which are pertinent for insulation design [10]. In this work, we present an investigation on interfacial charge between two dielectrics of different nature.…”

Study of Space Charge Dynamics in Oil and Pressboard Composite System under Different Polarity Reversal Voltages

“…IEC-61378-2 only requires that the whole polarity reversal process should be completed within 2 min. (16) The power industry usually turns off the applied voltage first, and then turns on the voltage with the opposite polarity after 2 min. In this study, for simplisity, the external voltage is directly removed during this stage.…”