Journal of Electrical Engineering and Technology

The Korean Institute of Electrical Engineers (대한전기학회)
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Analysis of Leak and Water Absorption Test Results for Water-Cooled Generator Stator Windings

  • Received : 2011.02.07
  • Accepted : 2011.10.16
  • Published : 2012.03.01
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Abstract

Cases of insulation breakdown damage of water-cooled generator stator windings occur frequently due to coolant leakage and water absorption worldwide. Such serious accidents may cause not only enormous economic loss but also very serious grid accidents in terms of stable supply of electric power. More than 50 % of domestic generators have been operated for more than 15 years, and leak and water absorption problem of windings are often found during the planned preventive maintenance period. Since 2005, leak and water absorption tests have been performed for total watercooled stator windings after fully drying the inside of the windings. The results are then comprehensively analyzed. The result of the test performed by GE, a foreign manufacturer, for 141 generators showed failures in 80 of them (failure rate: 57 %), whereas in the tests carried out in Korean domestic power plants, only 14 out of 50 generators showed failures (failure rate: 28 %).

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References

  1. GE Power Generation, Technical Information Letter- 1098, 1993
  2. Worden, A. Joseph, Mundulas, M. Jorge, 2001, "Understanding, Diagnosing, and Repairing Leaks in Water-Cooled Generator Stator Windings", GE Power Systems GER-3751A
  3. Lamberg, Alex, Tornross, Karl., 2004, "GE Generator Fleet Experience and Available Refurbishment Options", GE Energy GER-4223
  4. Bae, Y. C., Kim, H. S., Lee, D. Y., and Lee, W. R., 2008, "An Experimental Study on Water Absorption Characteristics of Generator Stator Bar Insulation by Cooling Water Temperature in 500MW capacity Power Plant", Trans. Korean Institute of Electrical Engineers, Vol. 57, No. 8, Aug, pp. 1392-1397
  5. Kim, H. S., Bae, Y. C., Lee, W. R., and Lee, D. Y., 2010, "An Experimental Study on the Dryness Judgment Criterion for Water-cooled Generator Stator Windings", J. of Korean Society of Mechanical Engineers(B), Vol. 34, No. 2, pp. 137-143 https://doi.org/10.3795/KSME-B.2010.34.2.137
  6. Kim, H. S., Bae, Y. C., Lee, W. R., and Lee, D. Y., 2010, "Experimental Study on Prediction and Diagnosis of Leakage and Water Absorption in Water-Cooled Generator Stator Windings by Drying Process Analysis", J. of Korean Society of Mechanical Engineers (B), Vol. 34, No. 9, pp. 867-873 https://doi.org/10.3795/KSME-A.2010.34.7.867
  7. Kim, H. S., Bae, Y. C. and Kee, C. D., 2008, "Wet Bar Detection by Using Water Absorption Detector", J. of Mechanical Science and Technology, Vol. 22, pp. 1163-1173 https://doi.org/10.1007/s12206-008-0404-y

Cited by

  1. Study on Reliability of Water Absorption Diagnosis through Precise Water Absorption Test vol.7, pp.5, 2012, https://doi.org/10.5370/JEET.2012.7.5.772
  2. Electrical Properties of Wet Bars in Water-cooled Generator Stator Windings vol.25, pp.10, 2012, https://doi.org/10.4313/JKEM.2012.25.10.817