On-line Transformer Winding Deformation Diagnosis:A Profound Insight to Methods

Monitoring and diagnosis of transformers have been investigated and discussed for many years. While transformer routine tests indicate electrical and also insulation weakness or defects, Frequency Response Analysis (FRA) as well as short circuit impedance can indicate mechanical defects in transformer active part. They have been using in last years as off line methods to reveal mechanical deformation in transformers. From monitoring point of view, on one hand smart grid studies have been expanded significantly and on-line monitoring of power equipment has changed positively; on the other hand transformer winding deformation is threatening transformer life inevitably and tends to put this valuable equipment out of service. Hence, all offline methods need to be modified to be applicable on-line, once transformer is in service. This study provides an insight to the problems pertaining transformer diagnostic methods, both on and off-line, characterizes existing online methods, explains the concepts behind online measurements in frequency domain and finally is striving to open the discussion doors towards advanced investigations which are all aligned with smart grid concept. This study has also concentrated partly on issues rising while on-line methods are going to be applied on transformers with various kinds of winding connections and accessories. In the end, crucial issues from theoretical and also practical perspectives for on-line transformer deformation diagnostic implementation as well as present gaps are discussed.

کلیدواژه ها:

On-line diagnosis ، Winding deformation ، Frequency response analysis ، Diagnosis methods