Compete Melt down of the damper winding in a synchronous generator
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.
Reason of Melting down of Damper windings
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.