Breakdown in Solid Dielectrics

Breakdown in Solid Dielectrics:

Breakdown in Composite Dielectrics : It is difficult to imagine a complete insulation system in an electrical equipment which does not consist of more than one type of insulation. If an insulation system as a whole is considered, it will be found that more than one insulating material is used. Breakdown in Solid Dielectrics …


Breakdown of Solid Dielectrics in Practice : There are certain types of breakdown which do not come under either intrinsic breakdown or thermal breakdown, but actually occur after prolonged operation. These are, for example, Breakdown in Solid Dielectrics due to tracking in which dry conducting tracks are formed on the surface of the insulation. These tracks act as conducting paths on the insulator surfaces leading …


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 is d0 and is compressed to a thickness d under an applied voltage V, then the electrically developed compressive stress is in equilibrium if where Y is the …


High Temperature High Performance Polymers : High Performance Polymers films are thermoplastic and are generally transparent. The are needed for use in applications where temperatures vary from very low (- 269°C) to very high (+ 400°C) values. Such applications include space shuttle solar arrays, high speed locomotive and other motor armature slot liners, capacitors, transformers, miniaturized electronic components, microprocessor chip carriers, cryogenic …


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. Experimentally, this highest dielectric strength can be obtained only under the best experimental conditions when all extraneous influences have been isolated and the value depends, only …


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 dielectric loss, high mechanical strength, should be free from gaseous inclusions, and moisture, and be resistant to thermal and chemical deterioration. Breakdown in Solid Dielectrics …


Breakdown of Solid Dielectrics in Practice : The majority of the insulating systems used in practice are solids. They can be broadly classified into three groups: organic materials, inorganic materials and synthetic polymers. Some of Solid Dielectrics Used in Practice materials are listed in Table 4.2 below. Paper and Boards The kind of paper normally employed for insulation purposes is a special variety known as …


Updated: April 29, 2020 — 9:40 pm