
Detection of inter turn fault in transformer windings by parameters of their transition processes
Author(s) -
Р. Г. Мустафин
Publication year - 2019
Publication title -
izvestiâ vysših učebnyh zavedenij. problemy ènergetiki
Language(s) - English
Resource type - Journals
eISSN - 2658-5456
pISSN - 1998-9903
DOI - 10.30724/1998-9903-2019-21-3-14-23
Subject(s) - energy efficient transformer , electromagnetic coil , leakage inductance , delta wye transformer , transformer , electrical engineering , inductance , rotary variable differential transformer , distribution transformer , current transformer , flyback transformer , isolation transformer , transformer effect , short circuit , engineering , linear variable differential transformer , voltage
The proposed method of detection the inter turn fault of transformer windings relates to the area of defectoscopy and allows detecting inter turn faults in a wide range of damaged (closed) turns. Power and instrument transformers with iron-core are widely used in power networks. As the insulation ages or is damaged, the wires between various transformer sections short circuits occur, which inevitably leads to a complete damage of the transformer. Short- circuited part of the transformer forms an additional winding, the outputs of which are short- circuited. The transition process of current increasing when DC voltage is connected to the transformer outputs occurs in diverse ways in undamaged (cut-off) winding section and in the damaged (short-circuited) section. The current growth rate in the undamaged section of the winding is determined by high magnetization inductance. The inductance of the short-circuited part of the winding is much less, so, the current growth rate in the short-circuited part is significantly greater than the current growth rate in the undamaged part of the winding. The article presents observations from computer models and real measurements of the substation auxiliary power transformer, which show the possibility of determining the presence of a turn fault in regards to the transition process parameters, the rate of current increase and decay in the transformer winding. The device aimed to find the inter turn faults in the transformer windings, working according to the proposed method will be quite simple and have a high sensitivity.