The Kerrelec electric-field distortions pr terials whenintroduced I chlorobiphenyl liquid insulb anAroclorl ofcommercial pendent oftheelectrical pr ontheliquid impurity level arealsoindependent ofth themeasured surface curre (EHD)circulation oftheIi distortions arediscussed il atthesolid-liquid interface

https://ieeexplore.ieee.org/iel5/14/4081804/04081807.pdf

Electric-Field Distortions atSolid-Liquid Dielectric Interfaces

Electrostrictive pressure measurements were obtained by the use of a holographic interferometer. Use of this technique permitted a determination of the local electric field in water when subjected to a high-voltage impulse. The interferometer was illuminated by a pulse laser, which enabled detailed images of the rapidly changing field to be captured in a single 20-ns exposure. Using the same test cell and laser, field measurements were also obtained by the Kerr electrooptical technique. A comparison of the electrostriction and Kerr-derived field maps yielded good correlation, and revealed a superior sensitivity for the electrostriction method. Analysis is presented that links fundamental polarization modeling with the electrostrictive field measurements. >

Optical field determination in water

A simulation study of streamer growth within a dielectric liquid at a solid interface was undertaken. Using the finite element method with computer graphics, the shape of the growing streamer was determined and plotted. In addition, the changing voltage and electric field values within the dielectric were calculated, and simulated images of these parameters produced. The behavior of the streamer is based on the formation of a localized gas phase discharge and the growth of the resulting plasma within the liquid. The model determines an inception site and predicts a growth path that depends on the electric field immediately surrounding the streamer tip. Two liquids, n-hexane and water, both with an interface, were investigated using the simulation model. The effect of the choice of the liquid and the solid dielectric, in addition to the geometry, was explored. For mixed solid and liquid insulation, the results show that streamer growth depends on the permittivity mismatch between the two materials. Experimental findings are presented that show streamer growth for different interfacial conditions. A good correlation is observed between the theoretical and experimental work.

Computer analysis and observation of streamer growth at a dielectric interface

A new experimental method is described in which the electrostrictive effect in a liquid is made visible. A real-time interferometer employing a Q-switched ruby laser was used to record transient optical disturbances. When a pulse voltage, synchronized with the laser pulse, was applied to the test object, interference fringes were produced in the viewing plane that could be recorded on photographic film. Experimental results are presented, together with a model for interpretation.

W. A. Pfuntner

Papers

Optical Electric Field Assessment in a Dielectric Liquid