Study of some factors affecting the breakdown strength of transformer oil

Several factors affect the breakdown strength of transformer oil. Oil motion increases the breakdown strength of the oil even if it is only a few cm/s. The gap effect expressed in kV/cm per decade change in gap spacing is greater than the corresponding electrode area effect. The volume effect cannot be expressed as a unique function of `area times gap spacing´ but rather as a function of the two components. It is suggested that the greater sensitivity to gap spacing is due to the faster accumulation of large particles in the gap, entering the stressed volume via the non-uniform field region at the electrode edges