Title :
Low-frequency dielectric response of epoxy-mica insulated generator bars during multi-stress aging
Author :
David, Eric ; Lamarre, Laurent
Author_Institution :
Ecole de Technologie Superieure, Montreal, Que.
Abstract :
The aging of insulating materials and insulating systems involves physical and/or chemical changes of the insulating material. These changes in turn lead to changes in the dielectric response of the insulating system. Quantitative measurements of the dielectric response function can be performed using either time or frequency domain techniques, both being mathematically related for linear systems. To investigate the evolution of the low-frequency dielectric response of epoxy-mica rotating machine insulation winding system as a function of aging, time domain dielectric measurements were conducted before, during and after a multi-stress aging program, using a full scale accelerated aging test facility. The results obtained in the investigation are reported in this paper. Modeling of the low-frequency dielectric response is also presented in this paper, with the model having been found to be in good agreement with the experimental results
Keywords :
ageing; dielectric measurement; epoxy insulation; frequency-domain analysis; insulation testing; life testing; machine insulation; machine testing; machine windings; mica; time-domain analysis; accelerated aging test; dielectric measurement; dielectric response; epoxy-mica insulation; frequency domain techniques; generator bars; insulating materials; multistress aging; rotating machine insulation winding; time domain techniques; Aging; Bars; Chemicals; Dielectric materials; Dielectric measurements; Dielectrics and electrical insulation; Frequency domain analysis; Frequency measurement; Performance evaluation; Time measurement;
Journal_Title :
Dielectrics and Electrical Insulation, IEEE Transactions on
DOI :
10.1109/TDEI.2007.302890
