Modelling of Relaxation Phenomena in Transformer Oil-Paper-Pressboard Insulation to determine the Dielectric Response Behaviour under DC and Impulse voltages

The factory acceptance tests are extremely important for the deployment and service life of Extra-high voltage transformers (EHV) and reactors. An essential part of such tests is Lightning Impulse (LI) tests which are intended to ensure that the transformer insulation withstands the transient lightning overvoltages which may occur while in...

A Piece-wise Linearized Transformer Winding Model for the Analysis of Internal Voltage Propagation

In this paper, a piece-wise linearized transformer winding model is proposed for transient internal voltage distribution computations. In particular, the model is based on the linearization of the primitive non-linear, frequency dependent and invariant matrix of voltage distribution factors. This primitive matrix is utilized as a pattern from...