Well, the obvious observation is that there was a large amount of current flowing through the damper winding.
The reason for the excessive current lays the answer to your question. You need to look at the unit and do some testing…
During comissioning of a small 1000 KW synchronous generator a failure occured in the Damper winding.
The customer supplied the following info. The stator breaker was open and the diesel was up to speed
When the operator pressed the button to start excitation the unit failed. The aluminum Damper winding completely melted. Damper winding failure are rare. Unclear what caused the failure? Anyone able to explain?
Unit destroyed.
Well, the obvious observation is that there was a large amount of current flowing through the damper winding.
The reason for the excessive current lays the answer to your question. You need to look at the unit and do some testing…
Dave your are exactly right. It is In process. Prelimanary testing on the generator show no defects in the Main stator winding or main rotor windings or exciter winding. The only way to get current flow in the damper winding is thru induction. With the stator winding breaker open induction does not seem likely.
...and the culprit was???
Nerdy minds need to know.
Dave
can you further explain the situation
Collapse of excitation may result into Generator pole slipping. If the synchronous generators are loaded in this condition , pole slipping may result into overheating of damper winding. and possible breakdown of rotating diodes/surge suppressors in case of brushless excitation syste. Pole slippage or field excitation failure is generally caused by faulty AVR System or due to exciter. Excitation failure is normally detected by Loss of filed protection on generator.