Effects Of Magnetic Field On Dielectric Breakdown Of Phenolic Resin And Polypropylene

Polymer materials such as phenolic resin and polypropylene are widely used as insulation material of electric and electronic devices for their great dielectric properties. With the development of the industry, the devices are often working in complex environment. For example, the magnetic field which around transformers and reactors would make dielectric breakdown of phenolic resin and polypropylene in the devices and finally result in serious failures. On the other hand, petrochemical organic materials also bring serious problems of pollution which have threatened people's lives. It is significant to open up the application of biodegradable insulation material. However, the effect of magnetic field on dielectric breakdown has not been sufficiently studied on phenolic resin and polypropylene. Therefore, from the reliability and safety point of view, it is important to investigate the influence of magnetic field on surface dielectric breakdown.In this paper, phenolic resin and biodegradable polypropylene were employed to investigate the effect of magnetic field on migration rate of surface carbonization and arc resistance. The experiment was carried out under electric and magnetic field by using a pulse power. The results showed that, with increase of the magnetic flux density, the migration rate of phenolic resin increased when E×B drifted into the surface but decreased when E×B drifted away from the surface. With increase of the electrode distance and discharge interval, the erosion depth of biodegradable polypropylene decreased and with increase of the atmospheric pressure, the erosion depth of biodegradable polypropylene increased. With increase of the magnetic flux density, the erosion depth decreased when the angle between magnetic field and electric filed is 90°but increased when the angle is 270°.