Electrode Systems for Dielectric Strenght Tests Controlling the Electro-Dielectrophoretic Effect

Two kinds of electrodes showing different behavior with respect to the impurity particles present in a dielectric fluid have been designed and built. Both electrodes have a uniform field region. The first kind is designed in order to avoid, as far as possible, the attraction of impurity particles into the test volume, whereas the second one is designed with the opposite aim. This is achieved by means of a special choice of the electrode profiles, which control the motion of particles by means of different field patterns. Some sets of experimental results on transformer oil confirming the theoretical expectations are presented and discussed.