Title :
Calculation of transformer winding resonances by a specialized finite element method employing substructures
Author :
Leohold, J. ; Silvester, P.P.
Author_Institution :
Inst. fur Elektrische Maschinen und Antriebe, Hannover Univ., West Germany
Abstract :
A method for the calculation of transformer winding resonances is derived which utilizes a specialized finite-element method to compute a ´dynamic´ impedance matrix. By modeling the high-frequency leakage field and conductor eddy currents the major sources of internal damping are included. The impedance matrix can be integrated for conventional transient analysis programs based on an equivalent-circuit approach. A substructuring technique in combination with the highly regular winding geometry is used to reduce computational requirements in the finite-element solution. The method is verified by comparison with measurements. Damping causes a shift of resonant frequencies and determines resonant amplitudes. Both effects show up well in the numerical results.<>
Keywords :
eddy currents; equivalent circuits; finite element analysis; power transformers; transformer windings; conductor eddy currents; conventional transient analysis programs; dynamic impedance matrix; equivalent-circuit approach; finite element method; high-frequency leakage field; internal damping; transformer winding resonances; Computational geometry; Conductors; Damping; Eddy currents; Finite element methods; Impedance; Resonance; Resonant frequency; Transient analysis; Windings;
Journal_Title :
Power Systems, IEEE Transactions on
