Insertion transformer modeling for improved high voltage regulation of a partial discharge analyzer for dielectric voltage breakdown analysis

Abstract

An accurate method of modeling a two winding transformer is presented. It is intended that ths type of modeling be completed before the physicall installation of a transformer into an existing electrical circuit. The first evaluation is to mathematically derive information from the transformer by means of physical measurements and calculations only. Next the electrical charactleristics are obtained by means of open and short circuit testing, where an actual potential is supplied, and measurements taken using digital and analog multi meters. Lastly a computer program is used to simulate: the modeled circuit. Data from all three tests is thein reviewed for correlation. The model used, a "T"-model, considers the capacitance of the windings to be negligible, and is ignored. The model presented also asc;umes that the inductive rea&" is much larger tha:n thie winding resistance, and therefore dominates. As will be seen, the close correlation of the data indicates that the assumptions that are made to do t h s analysis are valid.