appunni
Electrical
- Feb 11, 2003
- 52
Sir,
We have one 18MVA and 144 MVA units. In seperate occasions the megger values of stator windings were found low. The xd'',xd' and xd values of these units are about 15,25 and 90 percent respectively. These units are working in 11 kv system and the power is stepped up to higher voltage levels through delta /star generator transformers.
Can I heat the stator windings by applying 3phase,440v on the 3 phase windings of the units? Will the impedances of the windings be synchronous reactance of the unit even if the unit is standstill and the exciter is off?
What are the prcatical methods to pass current through stator windings in order to improve megger values?
I request for your valualble comments.
with regards,
appunni
We have one 18MVA and 144 MVA units. In seperate occasions the megger values of stator windings were found low. The xd'',xd' and xd values of these units are about 15,25 and 90 percent respectively. These units are working in 11 kv system and the power is stepped up to higher voltage levels through delta /star generator transformers.
Can I heat the stator windings by applying 3phase,440v on the 3 phase windings of the units? Will the impedances of the windings be synchronous reactance of the unit even if the unit is standstill and the exciter is off?
What are the prcatical methods to pass current through stator windings in order to improve megger values?
I request for your valualble comments.
with regards,
appunni