Review of space charge measurement systems: acoustic, thermal and optical methods

TLDR

Recent advances in space charge measurement have focused on acoustic and thermal techniques for insulation diagnostics. This review surveys the various space charge measurement techniques, outlining their working principles, key features, and principal applications. The article details the Pulsed Electro‑Acoustic method, its historical evolution, limits, and cell configurations, and similarly describes thermal methods while summarizing the basic principles and recent uses of optical techniques.

Abstract

In the last decade, remarkable developments have concerned the methods of space charge measurement in the field of insulation systems diagnostic. In particular, methods based on acoustic and thermal phenomena have been largely used. The present review provides a broad overview on the different techniques used describing, for each of them, the working principle, the main features and the most relevant applications. Further details are provided for the Pulsed Electro-Acoustic (PEA) method, as it seems to be the most used. This article provides more details on its historical evolution, showing evidence for its technological limits and taking into consideration the advantages and drawn from the different configurations of the measuring cell. A similar approach has been used for the group of thermal methods, whereas for the optical methods only the basic working principle and latest applications are reported.