Abstract—The use of partial discharge (PD) online
monitoring as an indicator of hydro-generator stator
insulation condition, is well known. In this paper, a set of
partial discharge online monitoring system for hydrogenerator
(HPDMS) with the characteristics of high
reliability is developed,and the de-noise method of the
system is introduced, In succession, the influence of PD
sensors installation on hydro-generator’s single phase
grounding fault is investigated. The system has
successfully checked out a stator insulation failure, the
partial discharge trends when the stator winding is in
failure are shown and the reason of the failure is explained,
the actual failure of the stator winding is consistent with
the analysis result, which greatly increases the credibility of the
PD online monitoring technology.