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

Thi Thu Nga Vu,Séverine Le Roy,Gilbert Teyssedre,Christian Laurent

doi:10.3390/technologies5020027

Abstract

The development of high voltage direct current (HVDC) technologies generates new paradigms in research. In particular and contrary to the AC case, investigation of electrical conduction is not only needed for understanding the dielectric breakdown but also to describe the field distribution inside the insulation. Here, we revisit the so-called Maxwell–Wagner effect in multi-layered dielectrics by considering on the one hand a non-linear field dependent model of conductivity and on the other hand by performing space charge measurements giving access to the interfacial charge accumulated between different dielectrics. We show that space charge measurements give access to the amount of interfacial charge built-up by the Maxwell–Wagner effect between two dielectrics of different natures. Measurements also demonstrate that the field distribution undergoes a transition from a capacitive distribution to a resistive one, under long lasting stress.

Highlights

The development of high voltage links for energy transport under DC voltage (HVDC) is boosted by the new generation of converters and, at the same time, by the need to interconnect networks allowing reliable delivery of electric energy from regions of production to regions of consumption.These technologies bring about new paradigms associated with the design and the behavior under the stress of electrical insulation
Theisfield not uniform the bulk of the insulation due to space charge accumulation as pointed out previously
The field computed fromfrom the conductivity datadata is anisunderestimation of the value of the stress, which the conductivity an underestimation of maximum the maximum value of local the local stress, which constitutes a limitation of the macroscopic modelling approach and justifies the need to perform constitutes a limitation of the macroscopic modelling approach and justifies the need to perform direct direct measurements the field distribution.Measurements

Summary

Introduction

The development of high voltage links for energy transport under DC voltage (HVDC) is boosted by the new generation of converters and, at the same time, by the need to interconnect networks allowing reliable delivery of electric energy from regions of production to regions of consumption. These technologies bring about new paradigms associated with the design and the behavior under the stress of electrical insulation. The service voltage for Technologies 2017, 5, 27; doi:10.3390/technologies5020027 www.mdpi.com/journal/technologies

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Conclusion