Understanding the Discharge Activities in Transformer Oil under AC and DC Voltage Adopting UHF Technique
Design of Converter transformer insulation is a major
challenge. The insulation of these transformers is stressed by both
AC and DC voltages. Particle contamination is one of the major
problems in insulation structures, as they generate partial discharges
leading it to major failure of insulation. Similarly corona discharges
occur in transformer insulation. This partial discharge due to particle
movement / corona formation in insulation structure under different
voltage wave shapes, are different. In the present study, UHF
technique is adopted to understand the discharge activity and could
be realized that the characteristics of UHF signal generated under
low and high fields are different. In the case of corona generated
signal, the frequency content of the UHF sensor output lies in the
range 0.3-1.2 GHz and is not much varied except for its increase in
magnitude of discharge with the increase in applied voltage. It is
realized that the current signal injected due to partial
discharges/corona is about 4ns duration measured for first one half
cycle. Wavelet technique is adopted in the present study. It allows
one to identify the frequency content present in the signal at different
instant of time. The STD-MRA analysis helps one to identify the
frequency band in which the energy content of the UHF signal is
maximum.
[1] IEEE Trial use standard general requirements and test code for oil
immersed HVDC converter transformers, IEEE Std C57.129-1999, IEEE
USA.
[2] W. Kennedy, Recommended dielectric tests and test procedures for
converter transformers and smoothing reactors, IEEE Trans. On Power
Delivery, 1(3), (1986) pp161-166.
[3] R. Tobazeon, Behaviour of spherical and cylindrical particles in an
insulating liquid subjected to a DC uniform field, Conduction and
Breakdown in Dielectric Liquids,1993., ICDL '93., IEEE 11th
International Conference on 19-23, PP.415 - 420, 1993.
[4] M.D. Judd, O. Farish and B.F. Hampton, Excitation of UHF signals by
partial discharges in GIS, IEEE Trans. On dielectrics and electrical
insulation, Vol-3, pp213-228, 1996.
[5] M.D. Judd, O. Farish and B.F. Hampton, Excitation of UHF signals by
partial discharges in GIS, IEEE Trans. On dielectrics and electrical
insulation, 3(2), (1996), pp213-228.
[6] G.P. Cleary and M.D. Judd, UHF and current pulse measurement of
partial discharge activity in mineral oil, IEE Proc.- Sci. Meas. Technol.
153(2), (2006), pp47-54.
[7] A Cavallini, G.C. Montanari, F. Ciani, Analysis of partial discharge
phenomena in paper oil insulation system as a basis for risk assessment
evaluation, IEEE International Conference on Dielectric Liquids, pp241
- 244, 2005.
[8] A Convery and M D Judd, "Measurement of propagation characteristics
for UHF signals in transformer insulation materials", Proc. 13th Int.
Symp. on High Voltage Engineering (Delft), August 2003.
[9] M.D. Judd and O. Farish, A pulsed GTEM system for UHF sensor
calibration, IEEE Trans. on Instrumentation and measurement, Vol-47,
pp875-880, 1998.
[10] National Grid Company plc, Capacitive couplers for UHF partial
discharge monitoring, Technical guidance note: TGN(T)121, Issue 1,
Jan 1997.
[11] O. Rioul and M. Vetterli, Wavelet and Signal Processing, IEEE Signal
Processing Magazine, pp. 14 - 38, 1991.
[12] Mallat, S. G., A Theory for Multi resolution signal decomposition: The
wavelet representation. IEEE Transactions on Pattern Analysis and
Machine Intelligence, Vol. 11, No. 7 (1989), pp. 674- 693.
[13] A.M. Gaouda, M.M.A. Salama, M.R. Sultan and A.Y. Chikhani, Power
Quality Detection and classification using Wavelet- Multi resolution
Signal Decomposition, IEEE Trans. on Power delivery, Vol. 14, No. 4,
pp. 1469 - 1476, 1999.
[14] M. Krins, H. Borsi and E. Gockenbach, Influence of carbon particle on
the breakdown voltage of transformer oil,12th Int. conf. On conduction
and breakdown in dielectric liquids (ICDL) Rome, Italy, pp296-299,
1996.
[15] S. Birlasekaran, The movement of a conductive particle in transformer
oil in AC fields, IEEE Trans. on Electrical Insulation, 28(1), (1993),
pp9-17.
[16] S. Birlasekaran, The measurement of charge on single particles in
transformer oil, IEEE Trans. on Electrical Insulation, 26(6), (1991)
pp1094-1103.
[17] Lucian Dascalescu, Michaela Mihaiescu, Robert Tobazeon, Modeling of
conductive particle behavior in insulating fluids affected by DC electric
fields, IEEE Trans. On Industry Applications, 34(1), (1998), pp66-74.
[18] M.D. Judd, Li Yang, Ian B.B. Hunter, Partial discharge monitoring for
power transformers using UHF sensors Part-1: Sensors and signal
interpretation, IEEE Electrical Insulation magazine, 21(2), (2005), pp5-
14.
[19] M.D. Judd, Li Yang, Ian B.B. Hunter, Partial discharge monitoring for
power transformers using UHF sensors Part-2: Field Experience, IEEE
Electrical Insulation Magazine, 21(3), (2005) 5-13.
[20] Sander Meijer, Edward Gulski, Johan J. Smit, H.F. Reijnders, sensitivity
check for UHF Partial discharge detection in power transformers, Conf.
Record of the 2004 IEEE int. conf. on Electrical Insulation, pp58-61,
Sept. 2004, Indianapolis, USA.
[21] K. Raja and S. Lelaidier, Experience with UHF partial discharge
measurement, Proc of 14th Int. conf. on dielectric liquids, pp239-241,
2002.
[1] IEEE Trial use standard general requirements and test code for oil
immersed HVDC converter transformers, IEEE Std C57.129-1999, IEEE
USA.
[2] W. Kennedy, Recommended dielectric tests and test procedures for
converter transformers and smoothing reactors, IEEE Trans. On Power
Delivery, 1(3), (1986) pp161-166.
[3] R. Tobazeon, Behaviour of spherical and cylindrical particles in an
insulating liquid subjected to a DC uniform field, Conduction and
Breakdown in Dielectric Liquids,1993., ICDL '93., IEEE 11th
International Conference on 19-23, PP.415 - 420, 1993.
[4] M.D. Judd, O. Farish and B.F. Hampton, Excitation of UHF signals by
partial discharges in GIS, IEEE Trans. On dielectrics and electrical
insulation, Vol-3, pp213-228, 1996.
[5] M.D. Judd, O. Farish and B.F. Hampton, Excitation of UHF signals by
partial discharges in GIS, IEEE Trans. On dielectrics and electrical
insulation, 3(2), (1996), pp213-228.
[6] G.P. Cleary and M.D. Judd, UHF and current pulse measurement of
partial discharge activity in mineral oil, IEE Proc.- Sci. Meas. Technol.
153(2), (2006), pp47-54.
[7] A Cavallini, G.C. Montanari, F. Ciani, Analysis of partial discharge
phenomena in paper oil insulation system as a basis for risk assessment
evaluation, IEEE International Conference on Dielectric Liquids, pp241
- 244, 2005.
[8] A Convery and M D Judd, "Measurement of propagation characteristics
for UHF signals in transformer insulation materials", Proc. 13th Int.
Symp. on High Voltage Engineering (Delft), August 2003.
[9] M.D. Judd and O. Farish, A pulsed GTEM system for UHF sensor
calibration, IEEE Trans. on Instrumentation and measurement, Vol-47,
pp875-880, 1998.
[10] National Grid Company plc, Capacitive couplers for UHF partial
discharge monitoring, Technical guidance note: TGN(T)121, Issue 1,
Jan 1997.
[11] O. Rioul and M. Vetterli, Wavelet and Signal Processing, IEEE Signal
Processing Magazine, pp. 14 - 38, 1991.
[12] Mallat, S. G., A Theory for Multi resolution signal decomposition: The
wavelet representation. IEEE Transactions on Pattern Analysis and
Machine Intelligence, Vol. 11, No. 7 (1989), pp. 674- 693.
[13] A.M. Gaouda, M.M.A. Salama, M.R. Sultan and A.Y. Chikhani, Power
Quality Detection and classification using Wavelet- Multi resolution
Signal Decomposition, IEEE Trans. on Power delivery, Vol. 14, No. 4,
pp. 1469 - 1476, 1999.
[14] M. Krins, H. Borsi and E. Gockenbach, Influence of carbon particle on
the breakdown voltage of transformer oil,12th Int. conf. On conduction
and breakdown in dielectric liquids (ICDL) Rome, Italy, pp296-299,
1996.
[15] S. Birlasekaran, The movement of a conductive particle in transformer
oil in AC fields, IEEE Trans. on Electrical Insulation, 28(1), (1993),
pp9-17.
[16] S. Birlasekaran, The measurement of charge on single particles in
transformer oil, IEEE Trans. on Electrical Insulation, 26(6), (1991)
pp1094-1103.
[17] Lucian Dascalescu, Michaela Mihaiescu, Robert Tobazeon, Modeling of
conductive particle behavior in insulating fluids affected by DC electric
fields, IEEE Trans. On Industry Applications, 34(1), (1998), pp66-74.
[18] M.D. Judd, Li Yang, Ian B.B. Hunter, Partial discharge monitoring for
power transformers using UHF sensors Part-1: Sensors and signal
interpretation, IEEE Electrical Insulation magazine, 21(2), (2005), pp5-
14.
[19] M.D. Judd, Li Yang, Ian B.B. Hunter, Partial discharge monitoring for
power transformers using UHF sensors Part-2: Field Experience, IEEE
Electrical Insulation Magazine, 21(3), (2005) 5-13.
[20] Sander Meijer, Edward Gulski, Johan J. Smit, H.F. Reijnders, sensitivity
check for UHF Partial discharge detection in power transformers, Conf.
Record of the 2004 IEEE int. conf. on Electrical Insulation, pp58-61,
Sept. 2004, Indianapolis, USA.
[21] K. Raja and S. Lelaidier, Experience with UHF partial discharge
measurement, Proc of 14th Int. conf. on dielectric liquids, pp239-241,
2002.
@article{"International Journal of Architectural, Civil and Construction Sciences:57354", author = "R. Sarathi and G. Koperundevi", title = "Understanding the Discharge Activities in Transformer Oil under AC and DC Voltage Adopting UHF Technique", abstract = "Design of Converter transformer insulation is a major
challenge. The insulation of these transformers is stressed by both
AC and DC voltages. Particle contamination is one of the major
problems in insulation structures, as they generate partial discharges
leading it to major failure of insulation. Similarly corona discharges
occur in transformer insulation. This partial discharge due to particle
movement / corona formation in insulation structure under different
voltage wave shapes, are different. In the present study, UHF
technique is adopted to understand the discharge activity and could
be realized that the characteristics of UHF signal generated under
low and high fields are different. In the case of corona generated
signal, the frequency content of the UHF sensor output lies in the
range 0.3-1.2 GHz and is not much varied except for its increase in
magnitude of discharge with the increase in applied voltage. It is
realized that the current signal injected due to partial
discharges/corona is about 4ns duration measured for first one half
cycle. Wavelet technique is adopted in the present study. It allows
one to identify the frequency content present in the signal at different
instant of time. The STD-MRA analysis helps one to identify the
frequency band in which the energy content of the UHF signal is
maximum.", keywords = "Contamination, Insulation, Partial Discharges,
Transformer oil, UHF sensors.", volume = "2", number = "3", pages = "49-8", }