Title :
Low-frequency dielectric response of asphalt bonded insulation
Author :
David, E. ; Lamarre, L. ; Nguyen, D.N.
Author_Institution :
Ecole de Technol. Superieure, Montreal, Que., Canada
Abstract :
Low frequency dielectric response measurements were performed on asphalt-mica stator insulation of vertical axis hydro-generators. These measurements, used as a diagnostic test, were conducted using a high voltage dc source and measuring the charge and discharge currents after the application of voltage steps of various magnitudes. The same dielectric tests were also performed on individual coils removed from the winging at different location, i.e. near the neutral end, the middle of the phase and the line end. Both the level of the dielectric loss and the non-linearity factor were found to correlate well with the aging conditions of the coils, which were related to their position in the winding.
Keywords :
asphalt; coils; dielectric losses; discharges (electric); mica; windings; aging conditions; asphalt bonded insulation; asphalt-mica stator insulation; charge currents; coils; dielectric loss; dielectric tests; discharge currents; high voltage dc source; low-frequency dielectric response; nonlinearity factor; vertical axis hydro-generators; voltage steps; winding; Asphalt; Bonding; Charge measurement; Coils; Current measurement; Dielectric measurements; Dielectrics and electrical insulation; Performance evaluation; Testing; Voltage;
Conference_Titel :
Solid Dielectrics, 2004. ICSD 2004. Proceedings of the 2004 IEEE International Conference on
Print_ISBN :
0-7803-8348-6
DOI :
10.1109/ICSD.2004.1350399
