Asymmetry during load-loss measurement of three-phase three-limb transformers

DSpace/Manakin Repository

Asymmetry during load-loss measurement of three-phase three-limb transformers

Show full item record

Title: Asymmetry during load-loss measurement of three-phase three-limb transformers
Author: ESCARELA-PEREZ, R; KULKARNI, SV; KODELA, NK; OLIVARES-GALVAN, JC
Abstract: When the load-loss measurement test is conducted on three-phase transformers, an appreciable asymmetry is observed among the power readings of the three phases. This asymmetry is the result of two causes, viz. asymmetrical disposition of phases in space with respect to each other and unequal stray losses produced by phases. The disposition of phases leads to asymmetrical mutual impedances between phases and this is the principal contributor to the phenomenon. Another factor that may have an important contribution to the phenomenon is the deviation of the phase angle difference between the voltages of the three phase source (used during the test) from 120 degrees. The causes are analyzed using a detailed three-dimensional (3-D) finite-element (FE) simulation of a 31.5 MVA, 132/33 kV transformer. In addition, a six-port network impedance model is deduced from open-circuit 3-D FE simulations. The impedance model is able to reproduce any condition of the transformer (e.g., open-circuit, short-circuit or on-load conditions) since it captures all the transformer electromagnetic phenomena. The six-port network results are discussed in order to elaborately clarify the intriguing problem of asymmetrical load-loss distribution, which is important for both transformer manufacturers and users. The results are further explained through sequence components; of currents.
URI: http://dx.doi.org/10.1109/TPWRD.2007.899248
http://dspace.library.iitb.ac.in/xmlui/handle/10054/8243
http://hdl.handle.net/10054/8243
Date: 2007


Files in this item

Files Size Format View

There are no files associated with this item.

This item appears in the following Collection(s)

Show full item record

Search DSpace


Advanced Search

Browse

My Account