Transformers Magazine, Vol. 1 No. 1, 2014.
Izvorni znanstveni članak
Voltage Stresses on Solid-liquid Insulation of Large Power Transformers
Juliano Montanha
; Siemens Transformer Group
Sažetak
Due to the time cost replacement of a failed large power transformer, reliability and good performance in service are fundamentals for long-term operation.
Insulation coordination studies are the base to evaluate the occurrence of the most important transients like overvoltages, system disturbances, lightning discharges and switching operations which reach the transformer terminals connected to the system.
A set of dielectric tests are required to be performed at the manufacturer facilities as a function of the transformer insulation level according to the standards.
Such dielectric tests are mandatory to defne the main insulation transformer design such clearances between windings, windings to core and leads as well.
Therefore it is very important to understand how and where the voltages are distributed within the transformer during the dielectric tests.
This article presents an overview about the voltage distribution of the main dielectric tests within the winding assembly of a three phase 40 MVA 138/13,8kV wye-delta regulating transformer.
Ključne riječi
insulation design; dielectric test; main gap; feldplot
Hrčak ID:
186880
URI
Datum izdavanja:
8.4.2014.
Posjeta: 917 *