Fluid electrification measurements of transformer pressboard/oil insulation in a Couette charger

A Couette charger (CC) facility has been built to simulate flow electrification processes in transformers where transformer oil fills the annulus between coaxial cylindrical electrodes. Transient measurements with a step change in temperature have shown the charge density to change from an initial value to a new steady-state value, including cases of polarity reversal, both values dependent on the equilibrium moisture levels in oil and pressboard. Through a model that accounts for diffusion of charge from the paper-oil interface into the bulk of the oil, these measurements are used to deduce the equilibrium wall charge density. To help understand the effects of energization and to scale laboratory measurements at low voltages and low frequencies to operating transformers, a charge injection model was refined to examine the migration of double layer and injected charge in the imposed sinusoidally time-varying electric field. Good fits between this model and measurements are achieved. >

[1]  Markus Zahn,et al.  An absolute charge sensor of fluid electrification measurements , 1991 .

[2]  M. Zahn,et al.  Drift/diffusion conduction model for flow electrification , 1990, Annual Conference on Electrical Insulation and Dielectric Phenomena.

[3]  E. Howells,et al.  Static electrification effects in transformer oil circulating pumps , 1990 .

[4]  M. J. Lee,et al.  Tandem-chamber charge density monitor , 1990 .

[5]  James R. Melcher,et al.  Continuum properties from interdigital electrode dielectrometry , 1988 .

[6]  M. Zahn,et al.  Equilibrium electrification parameters inferred from Couette charger terminal measurements , 1988, 1988. Annual Report., Conference on Electrical Insulation and Dielectric Phenomena.

[7]  Markus Zahn,et al.  An absolute charge sensor for fluid electrification measurement , 1988, Conference Record of the 1988 IEEE International Symposium on Electrical Insulation.

[8]  Markus Zahn,et al.  Flow-induced charge accumulation in thin insulating tubes , 1988 .

[9]  Markus Zahn,et al.  Couette charger for measurement of equilibrium and energization flow electrification parameters: application to transformer insulation , 1988 .

[10]  D. W. Crofts.  The electrification phenomena in power transformers , 1988 .

[11]  D. Lyon.  Couette flow measurement of equilibrium and energization charging in transformer insulation , 1987 .

[12]  H. Miyao,et al.  Influence of AC and DC field on streaming electrification of transformer oil , 1986, Conference on Electrical Insulation & Dielectric Phenomena — Annual Report 1986.

[13]  T. V. Oommen,et al.  Static electrification properties of transformer oil , 1986, Conference on Electrical Insulation & Dielectric Phenomena — Annual Report 1986.

[14]  Flow electrification in transformer oil/cellulosic systems , 1986, Conference on Electrical Insulation & Dielectric Phenomena — Annual Report 1986.

[15]  Dan W. Crofts,et al.  The static electrification phenomena in power transformers , 1986, Conference on Electrical Insulation & Dielectric Phenomena — Annual Report 1986.

[16]  Steven Marc Gasworth,et al.  Electrification by liquid dielectric flow , 1986, Conference on Electrical Insulation & Dielectric Phenomena — Annual Report 1986.

[17]  Markus Zahn,et al.  Electrification problems resulting from liquid dielectric flow. Final report , 1986 .

[18]  T. Oommen,et al.  Eelectrostatic Charging Tendency of Transformer Oils , 1984, IEEE Transactions on Power Apparatus and Systems.

[19]  T. V. Oommen,et al.  Electrostatic Charging Tendency of Transformer Oils , 1984, IEEE Power Engineering Review.

[20]  Electrostatic charge relaxation in tank filling operations , 1983 .

[21]  M. Yasuda,et al.  Suppression of Static Electrification of Insulating Oil for Large Power Transformers , 1986, IEEE Power Engineering Review.

[22]  Graham Williams,et al.  Conference on Electrical Insulation and Dielectric Phenomena , 1982, IEEE Transactions on Electrical Insulation.

[23]  H. Okubo,et al.  Suppression of Static Electrification of Insulating Oil for Large Power Transformers , 1982, IEEE Transactions on Power Apparatus and Systems.

[24]  A. J. Reynolds,et al.  The Structure of Turbulent Plane Couette Flow , 1982 .

[25]  Ain A. Sonin,et al.  Theory for electric charging in turbulent pipe flow , 1982, Journal of Fluid Mechanics.

[26]  J. T. Leonard.  Generation of electrostatic charge in fuel handling systems: A literature survey , 1981 .

[27]  T. Nitta,et al.  Model Approach to the Static Electrification Phenomena Induced by the Flow of Oil in Large Power Transformers , 1980, IEEE Transactions on Power Apparatus and Systems.

[28]  Y. Miura,et al.  Static Electrification by Forced Oil Flow in Large Power Transformer , 1980, IEEE Transactions on Power Apparatus and Systems.

[29]  S. Shimizu,et al.  Electrostatics in Power Transformers , 1979, IEEE Transactions on Power Apparatus and Systems.

[30]  H. Miyao,et al.  A Calculation of Potential Distribution Caused by Static Electrification Owing to Oil Flow in a Oil-Paper Insulation System and it's Application to Partial Discharge Phenomena in Oil , 1979, IEEE Transactions on Power Apparatus and Systems.

[31]  N. Denbow,et al.  The design and performance of novel on-line electrostatic charge-density monitors, injectors and neutralisers for use in fuel systems , 1979 .

[32]  Electrostatic potential and field in a cylindrical tank containing charged liquid , 1977 .

[33]  S. Yasufuku,et al.  Electrokinetic Phenomena in Electrical Insulating Oil/Impregnated Cellulosic Pressboard Systems , 1977, IEEE Transactions on Electrical Insulation.

[34]  J T Leonard,et al.  Pro-static Agents in Jet Fuels , 1976 .

[35]  Y. Inoue,et al.  Electrokinetic phenomena in electrical insulating oil/impregnated cellulosic pressboard system , 1976, 1976 IEEE International Conference on Electrical Insulation.

[36]  I Ginsburgh,et al.  The static charge reducer , 1970 .

[37]  Kenneth A. Kobe,et al.  Advances in petroleum chemistry and refining , 1963 .

[38]  H. Schlichting.  Boundary Layer Theory , 1955 .

[39]  Geoffrey Ingram Taylor,et al.  Fluid Friction between Rotating Cylinders. I. Torque Measurements , 1936 .