18-02-2010, 12:30 PM
[attachment=2334]
TECHNIQUES FOR ONLINE DETECTION OF SHORTS IN TURBINE GENERATOR ROTOR
CAUSES FOR SHORTED TURNS
COIL FORESHORTENING
END-STRAP ELONGATION
FOREIGN MATERIAL CONTAMINATION
BLOCKING PROBLEMS
1.COIL FORESHORTENING
BODY CU CANT EXPAND FREELY
MINIMISE BY USING MATERIALS WITH
SUFFICIENT YIELD STRENGTHS
WHY DETECTION IS IMPORTANT
ROTOR UNBALANCE
VIBRATION
HIGHER FIELD CURRENT IS REQUIRED
HIGHER TEMPERATURE WILL RESULT
DIMINISHED CAPACITY
COMPARISON
FLUX PROBE TEST
Online detection is possible
Number and location of shorts can be determined
Give idea about whether the rotor have to rewound
TWIN SIGNAL TEST
Online detection is possible
No such provision
Here also
CONCLUSION
FLUX PROBE MEASUREMENT
METHOD IS ADVANTAGEOUS
