Proceedings of 2002 IEEE 14th International Conference on Dielectric Liquids. ICDL 2002 (Cat. No.02CH37319)
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Experimental investigation of complex ion formation in solution of transformer oil with iodine
- Trang 21-24
The processes of ion-complex formation (ionic pairs, triplets, dipole-dipole and ion-dipole clusters) and associated conductivity in liquid dielectrics are considered. Experimental method and results on ionization process in solution of transformer ion with iodine are discussed.
#Oil insulation #Conductivity #Dielectric liquids #Ionization #Electrons #Spontaneous emission #Purification #Equations #Size measurement #Protons
Transformer performance assessment
- Trang 317-320
In today's deregulated electricity industry, transformers constitute a significant asset for utilities. Asset owners are continually being asked to do more with less. To achieve this monumental task, utility managers need detailed information about the current capability of the transformer, based on its condition (aging and health). Transformer performance assessment (TPA) combines online and offl......
#Temperature #Petroleum #Hydrogen #Condition monitoring #Data visualization #Visual databases #Aging #Fault detection #Data acquisition #Cooling
Investigation of the behavior of microscopic bubbles in insulating liquids: transition from the inertial regime to the viscous one
- Trang 194-198
The dynamics of microscopic bubbles have been widely studied in low-viscous insulating liquids. The bubble motion (growth, collapse, rebound, etc.) is governed by inertial forces. In this paper, we analyse the bubble dynamics in viscous liquids (/spl mu/ > 3 mPl), and we observed that the implosion time of the bubble becomes more and more important than that obtained in slightly viscous liquids. W......
#Microscopy #Insulation #Dielectric liquids #Viscosity #Voltage #Power capacitors #Stress #Electric breakdown #Surface tension #Hydrocarbons
Dielectric measurements on cryogenic insulation systems
- Trang 225-227
For the operation of high temperature superconducting (HTS) devices liquid nitrogen (LN2) is necessary to cool the HTS conductor down to the operating temperature of about 77 K. Depending on the application in electrical power systems and high voltage devices, LN2 is also an attractive dielectric liquid. Some prototypes of cables, power and traction transformers and current limiters were built, bu......
#Dielectric measurements #Cryogenics #Dielectrics and electrical insulation #High temperature superconductors #Temperature dependence #Superconducting cables #Aging #Superconducting devices #Nitrogen #Conductors
Influence of hydrostatic pressure on the characteristics of discharges propagating on solid/liquid insulating interfaces under AC and DC voltages
- Trang 207-210
This paper is aimed at the influence of the hydrostatic pressure on the discharge propagating at the liquid/solid insulating interfaces under AC and DC voltages using a point-plane electrode arrangement. It is shown that different shapes of creepage discharges and associated currents can be initiated for the same experimental conditions indicating the existence of different propagation modes of di......
#Solids #Voltage #Electrodes #Power transformer insulation #Dielectric liquids #Surface discharges #Oil insulation #Optical propagation #Safety #Minerals
A model for a polar dielectric liquid exhibiting Cole-Davidson behavior
- Trang 17-20
Although many dielectric liquids do exhibit Debye behavior, or a close approximation to it, others exhibit behavior for which the plot of /spl epsiv/" against /spl epsiv/' as the frequency is varied is not a semicircle, but one of several possible other shapes. These shapes can be predicted by the adoption of the postulate that the liquid exhibits more than one discrete relaxation time, or a smoot......
#Dielectric liquids #Frequency #Shape #Permittivity #Equations #Polarization #Torque #Absorption #Laboratories #Energy loss
Study of orientation of liquid crystal molecules at interface by shear horizontal wave
- Trang 386-389
The director-orientation of a liquid crystal near an interface between a glass plate and a liquid-crystal layer is studied under propagation of a shear horizontal (SH) acoustic wave. An acoustic phase-delay of a SH wave device with various liquid-crystal director orientations, which is affected by the liquid-crystal director orientation, is measured. The fractional velocity change of the SH wave i......
#Liquid crystals #Acoustic waves #Liquid crystal devices #Glass #Acoustic propagation #Acoustic devices #Acoustic measurements #Phase measurement #Numerical analysis #Voltage
AC electric-field-induced fluid flow in microelectrode structures: scaling laws
- Trang 52-55
The motion of polarizable bioparticles under the action of non-uniform ac electric fields is known as dielectrophoresis. Because submicrometre particles are subjected to Brownian motion, high electric fields are needed to manipulate them. However, these high electric fields give rise to fluid motion, which in turn results in a viscous drag on the particles. The electric fields generate beat, leadi......
#Fluid flow #Microelectrodes #Electric fields #Nonuniform electric fields #Polarization #Dielectrophoresis #Drag #Conductivity #Permittivity #Electrothermal effects
The behaviour of low conducting liquid in modulated electric field
- Trang 425-428
The electrothermoconvective instability of a low conducting liquid in modulated electric field of a plane horizontal capacitor is investigated in the electrohydrodynamic (EHD) approximation for arbitrary field modulation frequencies and various shapes (harmonic and triangular). The charge formation is produced either due to dielectrophoresis or due to the nonhomogeneous conductivity. The Floquet t......
#Stability #Shape #Conductivity #Frequency #Amplitude modulation #Voltage #Permittivity #Dielectric liquids #Temperature #Capacitors
A practical method for lifetime estimation of the used mineral oils
- Trang 305-308
Mineral oil, with the main roles of insulating and cooling in power transformers, is very similar to the blood in human body. Because of the importance of power transformers in electrical networks, permanent care of the oil quality is indispensable. In this paper, a practical method for estimation of a used transformer oil's lifetime is presented. Different kinds of tests, according to standards, ......
#Life estimation #Lifetime estimation #Minerals #Petroleum #Oil insulation #Power transformers #Power transformer insulation #Cooling #Blood #Humans