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Time-Variant evaluation of electromagnetic forces on transformer windings during inrush current and short-circuit by FEM

Eslami, A ; Sharif University of Technology | 2013

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  1. Type of Document: Article
  2. DOI: 10.1007/s13369-012-0362-7
  3. Publisher: 2013
  4. Abstract:
  5. Time-variant axial and radial electromagnetic for ces under inrush current and short-circuit current are calculated (by finite element method; FEM) and compared. A simplified analytic method is presented for computation of inrush current in transformer. The simulation results obtained by this method are compared with the measured values. A compact three-phase, core-type 132/20 KV, 30 MVA, power transformer is modeled, employing two-dimensional (2D) FEM, the different forces under short-circuit and inrush current conditions are evaluated as a function of time. The simulation results for this sample transformer show that the inrush current axial force is larger than clamping force (which is equal to the net downward axial force that is exerted on the windings during the steady state short-circuit condition) even 2. 4 s after energizing the transformer. Since the inrush current lasts longer and normally occurs more frequently than a short-circuit current in a power transformer (while, at present, it is not covered by the standard tests or transformer design procedures), it can be a serious threat to damage of transformer windings
  6. Keywords:
  7. Electromagnetic force ; Finite-element method ; Inrush current ; Power transformer ; Short circuit ; Time-variant
  8. Source: Arabian Journal for Science and Engineering ; Volume 38, Issue 4 , 2013 , Pages 883-893 ; 13198025 (ISSN)
  9. URL: http://link.springer.com/article/10.1007%2Fs13369-012-0362-7