On-line diagnostics of transformer winding insulation failures, by Park`s vector approach

This paper presents a non-invasive approach for diagnosing winding insulation failures in three-phase transformers, which is based on the on-line monitoring of the primary and secondary current Park's Vector. Experimental and simulated results demonstrate the effectiveness of the proposed technique, for detecting winding inter-turn insulation faults in operating three-phase transformers.

Parameters determination for the coupled electromagnetic transformer model, with particular reference to winding faults studies

In the past few years, a considerable research effort has been devoted to the development of transformer digital models in order to simulate its behaviour under transient and abnormal operating conditions. Although many three-phase transformer models have been presented in the literature, there is a surprisingly lack of studies regarding the incorporation of winding faults. This paper presents a coupled electromagnetic transformer model for the study of winding inter-turn short-circuits. Particular attention will be given to the model parameters determination, for both healthy and faulty operating conditions. Experimental and simulation test results are presented in the paper, demonstrating the adequacy of the model as well as the methodologies for the parameters determination.

Three-phase, three-limb, steady-state transformer model

This paper presents the development and implementation of a digital simulation model of a threephase, three-leg, three-winding power transformer. The proposed model, implemented in MATLAB environment, is based on the simultaneous analysis of both magnetic and electric lumped-parameters equivalents circuits, and it is intended to study its adequacy to incorporate, at a later stage, the influences of the occurrence of windings interturn short-circuit faults. Both simulation and laboratory tests results, obtained so far, for a three-phase, 6 kVA transformer, demonstrate the adequacy of the model under normal operating conditions.

Planning and design in postindustrial land transformation: east bank Arade river, Lagoa - case study

Tese de dout., Ciências e Tecnologias do Ambiente (Planeamento Urbano), Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2011