Measurements of charge formation in dielectric liquids in a cylindrical geometry

A method for studies of charge formation in dielectric liquids at high local electric field strength, utilizing a very thin wire surrounded by a cylindrical electrode, is presented. The space charge formed around the wire suppresses the maximum electric field, thereby reducing further charge formation. The charge build-up is therefore most easily studied immediately after voltage application. The measured initial current response has been shown to be correlated to the breakdown voltage. Space charge creation and transport have also been studied with computer simulations, and liquid properties influencing the current response as well as the breakdown voltage have been identified