Title :
Effect of repetitive impulse voltage on models of EHV transformer windings to determine ageing of paper insulation
Author :
Bhoomaiah, A. ; Mukherji, S. ; Gupta, S.C. ; Murthy, T.S.R. ; Singh, B.P.
Author_Institution :
Corporate Res. & Dev., Bharat Heavy Electr. Ltd., Hyderabad, India
Abstract :
Impulse testing of transformer involves a defined sequence of impulse applications at the specified voltage levels. However, in case of failure/damage during these tests, the winding gets subjected to repeated impulse shots, after repair. In this paper the effect of such repetitive impulses on transformer insulation has been investigated. Typical thicknesses of insulating paper as well as disc-to-disc winding models have been subjected to repetitive impulse stresses as encountered in actual service. The performance has been monitored at regular intervals by measurement of tensile strength and degree of polymerization (DP) for paper and partial discharge (PD) parameters of winding models.
Keywords :
impulse testing; insulation testing; paper; partial discharge measurement; polymerisation; power transformer insulation; power transformer testing; tensile strength; transformer windings; EHV transformer winding; ageing; disc-to-disc winding model; impulse shot; impulse stress; impulse testing; paper insulation; partial discharge measurement; performance monitoring; polymerization degree; repetitive impulse voltage; tensile strength measurement; Aging; Electrodes; Impulse testing; Oil insulation; Partial discharges; Power transformer insulation; Power transformers; Tensile stress; Thermal stresses; Windings;
Conference_Titel :
Electrical Insulation and Dielectric Phenomena, 2005. CEIDP '05. 2005 Annual Report Conference on
Print_ISBN :
0-7803-9257-4
DOI :
10.1109/CEIDP.2005.1560657
