Effects of magnetic field on treeing process in silicone rubber considering pulse voltage

Abstract

Magnetic field, produced by high current, accompanying with the electric field can generate electro-magnetic force in HVDC system, which enormously affects the treeing growth characteristics. Electrical tree behavior of silicone rubber(SiR)was investigated by stressed with repetitive pulse voltage considering magnetic field. The pulse frequency was set to 200 Hz, while the stressed pulse amplitude was ranged from 6 to 12 kV. The magnetic flux density (B) of the magnetic field was 100, 200 and 400 mT respectively. Electrical tree patterns, tree length and tree breakdown characteristics were fully studied. The results were presented from experimental investigations in order to characterize electrical tree as a function of the stressed pulse amplitude. Results show that the pulse amplitude plays a leading role in the propagation and breakdown processes of the electrical tree. It also indicates that tree structure is greatly dependent on the B of magnetic field. Results show that magnetic field promotes the tree propagation and accelerates the treeing process.