Simultaneous ultrawide and narrowband detection of PD pulses in dielectric liquids

Simultaneous narrow band (300 kHz) and wide band (500 MHz) measurements were carried out to obtain estimates of the apparent charge transfer associated with discrete isolated discharge pulses and discharge pulse bursts, which are observed to occur in dielectric liquids when wide band detection systems are utilized. The integrated apparent charge transfers determined with the narrow band system ranged from 12 to 95 pC, which represents typically the lower range of values normally encountered with PD activity in dielectric liquid-filled or impregnated equipment. While the discharge phenomena in perfluoro polyether liquids was found to be typified by sporadic appearances of single isolated pulses involving charge transfers between 33 and 38 pC, the discharge events in mineral oils assumed most frequently the form of pulse bursts, displaying the usual pulse sequences of quasi-ascending amplitudes; the overall integrated apparent charge transfer of the observed pulse bursts extended commonly from 12 to 16 pC. The charge release, occurring with the first (initiating) smallest discharge pulse within the pulse bursts, was estimated to be of the order of /spl sim/1 pC.

[1]  E. Forster,et al.  Streamer formation in perfluoropolyether under impulse conditions , 1993 .

[2]  R. Bartnikas.  Effect of Pulse Rise Time on the Response of Corona Detectors , 1972, IEEE Transactions on Electrical Insulation.

[3]  Massimo Pompili,et al.  Early stages of negative PD development in dielectric liquids , 1995 .

[4]  Simultaneous measurements of PD in oil using conventional narrow band and ultra wide band detection systems , 1996, ICDL'96. 12th International Conference on Conduction and Breakdown in Dielectric Liquids.

[5]  E. O. Forster,et al.  Partial discharges and streamers in liquid dielectrics-the significance of the inception voltage , 1993 .

[6]  Ryszard Malewski,et al.  Comparison of Three Techniques of Partial Discharge Measurements in Power Transformers , 1985, IEEE Transactions on Power Apparatus and Systems.

[7]  R. Bartnikas,et al.  A Commentary on Partial Discharge Measurement and Detection , 1987, IEEE Transactions on Electrical Insulation.

[8]  R. Bartnikas,et al.  On the character of different forms of partial discharge and their related terminologies , 1993 .

[9]  R. Bartnikas.  Partial Discharge Diagnostics: A Utility Perspective , 1994 .

[10]  Edward F. Kelley,et al.  Measurement of partial discharges in hexane under DC voltage , 1989 .

[11]  R. Bartnikas,et al.  Effect of overvoltage on the risetime and amplitude of PD pulses , 1995 .

[12]  O. Lesaint,et al.  Streamer generation and propagation in transformer oil under divergent field conditions , 1987, 1987 Ninth International Conference on Conduction and Breakdown in Dielectric Liquids.

[13]  Massimo Pompili,et al.  Partial discharge distributions in liquid dielectrics , 1992 .

[14]  R. Bartnikas,et al.  Theoretical and experimental investigations on the process of high-pressure discharge development , 1991 .

[15]  Massimo Pompili,et al.  The effect of the definition used in measuring partial discharge inception voltages , 1993 .

[16]  R. Bartnikas,et al.  Ionization and excitation behavior in a microcavity , 1995 .

[17]  Massimo Pompili,et al.  A study of partial discharge measurements in dielectric liquids , 1992 .