抄録
In this study, the author investigated the online deterioration diagnosis of hydro-generators. Simultaneous measurements were done under offline conditions by using an online PD monitor and an offline PD measuring system. When a stator had wave-winding structure, good correlation between the maximum electric discharges and PD values of the online PD monitor was seen. However, when a stator had lap-winding structure, a good correlation could not be seen clearly. PD values were small due to the weak capacitive coupling in a lap-winding structure. PD measurement of hydro-generators with wave-winding structure was done under online and offline conditions by using the PD monitor. Online PD values were slightly higher than offline PD values. The author believes that online PD monitoring is useful in diagnosis of hydro-generators when the stator has wave-winding structure.
