EXPERIENCES IN IDENTIFICATION OF PARTIAL DISCHARGE PATTERNS IN LARGE HYDROGENERATORS

摘要

In this paper some experiences on partial discharge (PD) pattern identification in hydrogenerators from 103 to 805 MVA at the Guri and Macagua II power stations in Venezuela are presented. Visual inspections and measurements were carried out for partial discharge pattern identification in several different generators. In addition to these results, simultaneous measurements of on-line partial discharges were performed with vibration measurements on the stator core and frame under different operating conditions. Ozone concentration was also evaluated. Since slot discharges are directly relates with movement in slots and to determine how load conditions would affect magnetic forces over stator bars and their movement on the slot, simulations by FEM were performed.