Study of power transformer excitation under GIC

This paper describes transformer excitation under the influence of geomagnetically induced currents (GIG). An equivalent magnetic circuit model based on 3D finite element magnetic flux distribution analysis was developed to replace the constant magnetizing inductance of the conventional equivalent Tee circuit. The modified nonlinear equivalent circuit is capable of simulating transformer performance under a wide range of GIC levels. Using a single phase transformer example, the effect of each lumped component in the Tee circuit (leakage inductances, winding resistances, core loss resistance) on the excitation current is studied in detail.<<ETX>>

[1]  R. A. Walling,et al.  Characteristics of transformer exciting-current during geomagnetic disturbances , 1991 .

[2]  A. Yacamini,et al.  Harmonics produced by direct current in convertor transformers , 1978 .

[3]  Ewald F. Fuchs,et al.  Large signal nonlinear model of anisotropic transformers for nonsinusoidal operation. II. Magnetizing and core-loss currents , 1991 .

[4]  N. Mohan,et al.  Harmonics and Switching Transients in the Presence of Geomagnetically-Induced Currents , 1981, IEEE Transactions on Power Apparatus and Systems.

[5]  L. Bolduc,et al.  Effects of direct currents in power transformers Part I. A general theoretical approach , 1978 .

[6]  N. Mohan,et al.  Current Transformer and Relay Performance in the Presence of Geomagnetically-Induced Currents , 1981, IEEE Transactions on Power Apparatus and Systems.

[7]  M.A.S. Masoum,et al.  Large Signal Nonlinear Model of Anisotropic Transformers for Nonsinusoidal Operation, Part I: /spl lambda/ - i Characteristic , 1991, IEEE Power Engineering Review.

[8]  R. S. Girgis,et al.  Calculation techniques and results of effects of GIC currents as applied to two large power transformers , 1991, Proceedings of the 1991 IEEE Power Engineering Society Transmission and Distribution Conference.

[9]  L. Bolduc,et al.  Effects of direct currents in power transformers Part II. Simplified calculations for large transformers , 1978 .

[10]  S. Lu,et al.  Modelling of power transformer excitation under GIC/SMD , 1993 .

[11]  J. De La Ree,et al.  Harmonics generated from a DC biased transformer , 1992 .