INFLUENCE OF INSULATOR ALONG THE PLANE OF SYMMETRY OF A BLADE-PLANE GAP ON I-V CHARACTERISTICS IN TRANSFORMER OIL

In the case of a blade-plane electrode geometry in transformer oil, co nduction currents under de stresses were exceedingly decreased by a so lid insulator inserted along the plane of symmetry of an electrode gap whatever the polarity of the blade. However, the stationary relations hip between current I and voltage V always showed the linear plots of V vs. I-1/3. The effect of the insulator on the current is discussed o n the basis of the electrohydrodynamic (EHD) motion as well as the ele ctric field of the blade edge taking into account the insulator surfac e charging.