30-10-2012, 02:12 PM
TECHNIQUES FOR ONLINE DETECTION OF SHORTS IN TURBINE GENERATOR ROTOR
TECHNIQUES FOR ONLINE.pptx (Size: 1.35 MB / Downloads: 31)
CAUSES FOR SHORTED TURNS
END-STRAP ELONGATION
FOREIGN MATERIAL CONTAMINATION
BLOCKING PROBLEMS
BLOCKING PROBLEMS
AS AGE OF UNIT INCREASES BLOCKING
PROBLEMS ALSO INCREASES
WHY DETECTION IS IMPORTANT?
ROTOR UNBALANCE
VIBRATION
HIGHER FIELD CURRENT IS REQUIRED
HIGHER TEMPERATURE WILL RESULT
TWIN SIGNAL SENSING METHOD
PRINCIPLE
COMPONENTS
HOW CAN WE DETECT SHORTS?
TESTING ON TRANSFORMER
Tested on a transformer windings with AC excitation which has facility for creating temporary short at various points.
This rotor has 4 poles and 12 slots with two concentric coils per pole. The inner concentric coil has 36 turns and the outer coil has 18 turns. Thus, each slot has 36 conductors.
All the 4 windings are connected in series with appropriate polarity
CONCLUSION
The twin-signal sensing technique has been shown to provide excellent results for on-line detection of faults in rotor windings of turbine-generators.
The technique is simple and needs only healthy rotor data.
The testing can be performed on-line for excited windings.
TECHNIQUES FOR ONLINE.pptx (Size: 1.35 MB / Downloads: 31)
CAUSES FOR SHORTED TURNS
END-STRAP ELONGATION
FOREIGN MATERIAL CONTAMINATION
BLOCKING PROBLEMS
BLOCKING PROBLEMS
AS AGE OF UNIT INCREASES BLOCKING
PROBLEMS ALSO INCREASES
WHY DETECTION IS IMPORTANT?
ROTOR UNBALANCE
VIBRATION
HIGHER FIELD CURRENT IS REQUIRED
HIGHER TEMPERATURE WILL RESULT
TWIN SIGNAL SENSING METHOD
PRINCIPLE
COMPONENTS
HOW CAN WE DETECT SHORTS?
TESTING ON TRANSFORMER
Tested on a transformer windings with AC excitation which has facility for creating temporary short at various points.
This rotor has 4 poles and 12 slots with two concentric coils per pole. The inner concentric coil has 36 turns and the outer coil has 18 turns. Thus, each slot has 36 conductors.
All the 4 windings are connected in series with appropriate polarity
CONCLUSION
The twin-signal sensing technique has been shown to provide excellent results for on-line detection of faults in rotor windings of turbine-generators.
The technique is simple and needs only healthy rotor data.
The testing can be performed on-line for excited windings.