Electromechanical Breakdown and Thermal Breakdown: Electromechanical Breakdown:When solid dielectrics are subjected to high electric fields, failure occurs due to electrostatic compressive forces which can exceed the mechanical compressive strength. If the thickness of the specimen…
Intrinsic Breakdown: When voltages are applied only for short durations of the order of 10-8 s the dielectric strength of a solid dielectric increases very rapidly to an upper limit called the intrinsic electric strength.…
Solid Dielectric Materials: Solid dielectric materials are used in all kinds of electrical apparatus and devices to insulate one'current carrying part from another when they operate at different voltages, A good dielectric should have low…
Conduction and Breakdown in Commercial Liquids: As already mentioned, Conduction and Breakdown in Commercial Liquids are not chemically pure and have impurities like gas bubbles, suspended particles, etc. These impurities reduce the breakdown strength of…
Conduction and Breakdown in Pure Liquids: When low electric fields less than 1 kV/cm are applied, conductivities of 10-18-10-20 mho/cm are obtained. Conduction and Breakdown in Pure Liquids are probably due to the impurities remaining…
Pure Liquids and Commercial Liquids: Pure liquids are those which are chemically pure and do not contain any other impurity even in traces of 1 in I09, and are structurally simple. Examples of such simple…
Characteristics of Liquid Dielectrics: Essential Characteristics of Liquid Dielectrics should possess good dielectric properties, excellent heat transfer characteristics and must be chemically stable under the range of conditions under which the equipment operates. These are briefly…
Classification of Liquid Dielectrics: In recent years, a substitute to mineral oils, other polyester oils have been developed which are extensively used in transformers in Europe and other countries. One such oil is the halogen free Penta-Etythrite-Tetra…
Liquid Dielectrics Breakdown: Liquid dielectrics, because of their inherent properties, appear as though they would be more useful as insulating materials than either solids or gases. This is because both liquids and solids are usually…
Vacuum Breakdown: In the Townsend type of discharge in a gas described earlier, electrons get multiplied due to various ionization processes and an electron avalanche is formed. In a high Vacuum Breakdown, even if the…
