Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings

Soo-hoh Lee; Hee-dong Kim; Tae-sik Kong

doi:doi:10.11648/j.epes.20190806.11

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Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings

Soo-hoh Lee, Hee-dong Kim, Tae-sik Kong

Published in American Journal of Electrical Power and Energy Systems (Volume 8, Issue 6)

Received: 23 September 2019 Accepted: 16 October 2019 Published: 4 November 2019

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Abstract

This study conducted and analyzed the results of non-destructive tests (AC current, dissipation factor, and partial discharge tests) and a destructive test (overvoltage test) on 26 kV-generator stator windings with a ground fault. The target generator was a steam turbine generator in operation for over 30 years, and ground fault in windings occurred because of the rapid and instantaneous temperature rise in the copper conductor owing to the partial loss of generator cooling water. By comparing the non-destructive test data measured during the planned preventive maintenance period two years before the ground fault and the data gathered just after the ground fault, the study conducted an in-depth analysis of the effect of moisture on insulation diagnosis factors. If both the dissipation factor and capacitance data increased when compared to those of previously estimated values at same applied AC voltage level, it represented that the insulation materials absorbed moisture. Moreover, it was further developed that both of the dissipation factor and capacitance surge voltage were detected when the discharge started whereas the concerned surge voltage for AC current was detected when the discharge was proceeded in some extent. It is expected that a wider understanding of insulation diagnosis factors developed from this study will contribute not only to a more reliable diagnosis data analysis but also a stable power supply by preventing accidents in advance.

Published in	American Journal of Electrical Power and Energy Systems (Volume 8, Issue 6)
DOI	10.11648/j.epes.20190806.11
Page(s)	145-151
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2019. Published by Science Publishing Group

Keywords

Insulation, Stator Winding, Generator, AC Current, Dissipation Factor, Capacitance, Partial Discharge, Overvoltage

References

[1]	H. D. Kim, “Analysis of Insulation Aging Mechanism in Generator Stator Windings,” J. Korean Inst. Electr. Electron. Mater. Eng., vol. 15, No. 2, pp. 119–126, 2002.
[2]	R. Morin, R. Bartnikas, and P. Menard, “A Three-Phase Multi-Stress Accelerated Electrical Aging Test Facility for Stator Bars,” IEEE Trans. on Electrical Conversion, vol. 15, No. 2, pp. 149–156, 2000.
[3]	H. D. Kim, T. S. Kong, S. K. Lee, B. S. Kim, and D. Y. Kim, “Analysis of Off-Line and On-Line Partial Discharge in High Voltage Motor Stator Windings,” J. Electr. Eng. Technol., vol. 10, No. 3, pp. 1086–31092, 2015.
[4]	H. D. Kim, “Analysis of Insulation Quality in Large Generator Stator Windings,” J. Electr. Eng. Technol., vol. 6, No. 2, pp. 384–390, 2011.
[5]	H. Zhu, V. Green, and D. Huynh, “Application of On-Line versus Off-Line PD Testing for Stator Insulation Monitoring,” Electrical Insulation Conference and Electrical Manufacturing & Coil Winding Conference, pp. 175–178, 1999.
[6]	T. S. Kong, H. D. Kim, T. S. Park, K. Y. Kim, and H. Y. Kim, “Analysis of Partial Discharge Patterns for Generator Stator Windings,” American J. Electrical Power Energy Sys., vol. 4, No. 2, pp. 17–22, 2015.
[7]	H. D. Kim, T. S. Kong, Y. H. Ju, and B. H. Kim, “Analysis of Insulation Quality in Large Generator Stator Windings,” Journal of Electrical Engineering & Technology, vol. 6, No. 2, pp. 384–390, 2011.
[8]	IEEE Standard, “IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery,” IEEE Std. 43, 2013.
[9]	Hazlee Illias, Teo Soon Yuan, Ab Halim Abu Bakar, Hazlie Mokhlis, George Chen, and Paul L. Lewin, “Partial Discharge Patterns in High Voltage Insulation,” IEEE International Conference on Power and Energy (PECon), pp. 750-755, 2012.
[10]	Wei Wang, Lin Yan, Tianzheng Wang, Hua Yu, Yu han, Xingting Liu, Na Zhang, and Na Wu, “PD Mechanism and Pattern Investigation for Stator Winding Insulation of HV Motors,” in Proceedings of 2016 IEEE International Conference on Mechatronics and Automation, Harbin, August 2016.
[11]	Claude Hudon and Mario Bélec, “Partial Discharge Signal Interpretation for Generator Diagnostics,” IEEE Trans. on Dielectrics and Electrical Insulation, vol. 12, No. 2, pp. 297–319, 2005.
[12]	H. D. Kim, T. S. Kong, T. S. Park, and T. H. Son, “Analysis of On-Line Partial Discharge Trend in Gas Turbine Generators”, International Journal of Energy and Power, vol. 3, no. 3, pp. 42-48, 2014.
[13]	H. D. Kim, T. S. Kong, S. K. Lee, B. S. Kim & D. Y. Kim “Analysis of off-line and on-line partial discharge in high voltage motor stator windings”, Journal of Electrical Engineering & Technology, Vol. 10, No. 3, pp. 1086–1092, 2015.
[14]	G. C. Stone, C. Chan, and H. G. Sedding, “On-line Partial Discharge Measurement in Hydrogen-Cooled Generators,” in 2016 IEEE Electrical Insulation Conference, Montréal, Canada, June 2016.
[15]	IEEE Standard, “IEEE Guide for Insulation Maintenance of Electric Machines,” IEEE Std. 56, 2016.

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APA Style

Soo-hoh Lee, Hee-dong Kim, Tae-sik Kong. (2019). Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings. American Journal of Electrical Power and Energy Systems, 8(6), 145-151. https://doi.org/10.11648/j.epes.20190806.11

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ACS Style

Soo-hoh Lee; Hee-dong Kim; Tae-sik Kong. Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings. Am. J. Electr. Power Energy Syst. 2019, 8(6), 145-151. doi: 10.11648/j.epes.20190806.11

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AMA Style

Soo-hoh Lee, Hee-dong Kim, Tae-sik Kong. Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings. Am J Electr Power Energy Syst. 2019;8(6):145-151. doi: 10.11648/j.epes.20190806.11

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@article{10.11648/j.epes.20190806.11,
  author = {Soo-hoh Lee and Hee-dong Kim and Tae-sik Kong},
  title = {Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings},
  journal = {American Journal of Electrical Power and Energy Systems},
  volume = {8},
  number = {6},
  pages = {145-151},
  doi = {10.11648/j.epes.20190806.11},
  url = {https://doi.org/10.11648/j.epes.20190806.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.epes.20190806.11},
  abstract = {This study conducted and analyzed the results of non-destructive tests (AC current, dissipation factor, and partial discharge tests) and a destructive test (overvoltage test) on 26 kV-generator stator windings with a ground fault. The target generator was a steam turbine generator in operation for over 30 years, and ground fault in windings occurred because of the rapid and instantaneous temperature rise in the copper conductor owing to the partial loss of generator cooling water. By comparing the non-destructive test data measured during the planned preventive maintenance period two years before the ground fault and the data gathered just after the ground fault, the study conducted an in-depth analysis of the effect of moisture on insulation diagnosis factors. If both the dissipation factor and capacitance data increased when compared to those of previously estimated values at same applied AC voltage level, it represented that the insulation materials absorbed moisture. Moreover, it was further developed that both of the dissipation factor and capacitance surge voltage were detected when the discharge started whereas the concerned surge voltage for AC current was detected when the discharge was proceeded in some extent. It is expected that a wider understanding of insulation diagnosis factors developed from this study will contribute not only to a more reliable diagnosis data analysis but also a stable power supply by preventing accidents in advance.},
 year = {2019}
}

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TY  - JOUR
T1  - Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings
AU  - Soo-hoh Lee
AU  - Hee-dong Kim
AU  - Tae-sik Kong
Y1  - 2019/11/04
PY  - 2019
N1  - https://doi.org/10.11648/j.epes.20190806.11
DO  - 10.11648/j.epes.20190806.11
T2  - American Journal of Electrical Power and Energy Systems
JF  - American Journal of Electrical Power and Energy Systems
JO  - American Journal of Electrical Power and Energy Systems
SP  - 145
EP  - 151
PB  - Science Publishing Group
SN  - 2326-9200
UR  - https://doi.org/10.11648/j.epes.20190806.11
AB  - This study conducted and analyzed the results of non-destructive tests (AC current, dissipation factor, and partial discharge tests) and a destructive test (overvoltage test) on 26 kV-generator stator windings with a ground fault. The target generator was a steam turbine generator in operation for over 30 years, and ground fault in windings occurred because of the rapid and instantaneous temperature rise in the copper conductor owing to the partial loss of generator cooling water. By comparing the non-destructive test data measured during the planned preventive maintenance period two years before the ground fault and the data gathered just after the ground fault, the study conducted an in-depth analysis of the effect of moisture on insulation diagnosis factors. If both the dissipation factor and capacitance data increased when compared to those of previously estimated values at same applied AC voltage level, it represented that the insulation materials absorbed moisture. Moreover, it was further developed that both of the dissipation factor and capacitance surge voltage were detected when the discharge started whereas the concerned surge voltage for AC current was detected when the discharge was proceeded in some extent. It is expected that a wider understanding of insulation diagnosis factors developed from this study will contribute not only to a more reliable diagnosis data analysis but also a stable power supply by preventing accidents in advance.
VL  - 8
IS  - 6
ER  -

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Author Information

Soo-hoh Lee

Power Generation Laboratory, Korea Electric Power Corporation (KEPCO) Research Institute, Dae-jeon, South Korea
Hee-dong Kim

Power Generation Laboratory, Korea Electric Power Corporation (KEPCO) Research Institute, Dae-jeon, South Korea
Tae-sik Kong

Power Generation Laboratory, Korea Electric Power Corporation (KEPCO) Research Institute, Dae-jeon, South Korea

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Plain Text BibTeX RIS

APA Style

Soo-hoh Lee, Hee-dong Kim, Tae-sik Kong. (2019). Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings. American Journal of Electrical Power and Energy Systems, 8(6), 145-151. https://doi.org/10.11648/j.epes.20190806.11

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ACS Style

Soo-hoh Lee; Hee-dong Kim; Tae-sik Kong. Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings. Am. J. Electr. Power Energy Syst. 2019, 8(6), 145-151. doi: 10.11648/j.epes.20190806.11

Copy | Download

AMA Style

Soo-hoh Lee, Hee-dong Kim, Tae-sik Kong. Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings. Am J Electr Power Energy Syst. 2019;8(6):145-151. doi: 10.11648/j.epes.20190806.11

Copy | Download

@article{10.11648/j.epes.20190806.11,
  author = {Soo-hoh Lee and Hee-dong Kim and Tae-sik Kong},
  title = {Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings},
  journal = {American Journal of Electrical Power and Energy Systems},
  volume = {8},
  number = {6},
  pages = {145-151},
  doi = {10.11648/j.epes.20190806.11},
  url = {https://doi.org/10.11648/j.epes.20190806.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.epes.20190806.11},
  abstract = {This study conducted and analyzed the results of non-destructive tests (AC current, dissipation factor, and partial discharge tests) and a destructive test (overvoltage test) on 26 kV-generator stator windings with a ground fault. The target generator was a steam turbine generator in operation for over 30 years, and ground fault in windings occurred because of the rapid and instantaneous temperature rise in the copper conductor owing to the partial loss of generator cooling water. By comparing the non-destructive test data measured during the planned preventive maintenance period two years before the ground fault and the data gathered just after the ground fault, the study conducted an in-depth analysis of the effect of moisture on insulation diagnosis factors. If both the dissipation factor and capacitance data increased when compared to those of previously estimated values at same applied AC voltage level, it represented that the insulation materials absorbed moisture. Moreover, it was further developed that both of the dissipation factor and capacitance surge voltage were detected when the discharge started whereas the concerned surge voltage for AC current was detected when the discharge was proceeded in some extent. It is expected that a wider understanding of insulation diagnosis factors developed from this study will contribute not only to a more reliable diagnosis data analysis but also a stable power supply by preventing accidents in advance.},
 year = {2019}
}

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TY  - JOUR
T1  - Characteristics of Indicators for Insulation Deterioration in 26 kV Generator Stator Windings
AU  - Soo-hoh Lee
AU  - Hee-dong Kim
AU  - Tae-sik Kong
Y1  - 2019/11/04
PY  - 2019
N1  - https://doi.org/10.11648/j.epes.20190806.11
DO  - 10.11648/j.epes.20190806.11
T2  - American Journal of Electrical Power and Energy Systems
JF  - American Journal of Electrical Power and Energy Systems
JO  - American Journal of Electrical Power and Energy Systems
SP  - 145
EP  - 151
PB  - Science Publishing Group
SN  - 2326-9200
UR  - https://doi.org/10.11648/j.epes.20190806.11
AB  - This study conducted and analyzed the results of non-destructive tests (AC current, dissipation factor, and partial discharge tests) and a destructive test (overvoltage test) on 26 kV-generator stator windings with a ground fault. The target generator was a steam turbine generator in operation for over 30 years, and ground fault in windings occurred because of the rapid and instantaneous temperature rise in the copper conductor owing to the partial loss of generator cooling water. By comparing the non-destructive test data measured during the planned preventive maintenance period two years before the ground fault and the data gathered just after the ground fault, the study conducted an in-depth analysis of the effect of moisture on insulation diagnosis factors. If both the dissipation factor and capacitance data increased when compared to those of previously estimated values at same applied AC voltage level, it represented that the insulation materials absorbed moisture. Moreover, it was further developed that both of the dissipation factor and capacitance surge voltage were detected when the discharge started whereas the concerned surge voltage for AC current was detected when the discharge was proceeded in some extent. It is expected that a wider understanding of insulation diagnosis factors developed from this study will contribute not only to a more reliable diagnosis data analysis but also a stable power supply by preventing accidents in advance.
VL  - 8
IS  - 6
ER  -

Copy | Download