PROJECT TITLE :

Control and suppression of impulse surface flashover in vacuum based on discharge development mechanisms

ABSTRACT:

Surface discharge on solid insulator in vacuum is one in all the numerous problems for the development of vacuum circuit breakers (VCBs) and vacuum interrupters (VIs). For the event of upper voltage VCBs and VIs, management and suppression techniques of the surface flashover are needed. The aim of gift study is to suppress the surface flashover, primarily based on physical mechanisms of flashover development. Impulse surface flashover in vacuum, beginning with explosive electron emission (EEE) from cathode, develops with the formation of transient charge on the insulator furthermore the development of secondary electron emission avalanche (SEEA) along the surface toward anode. To reduce the EEE current from the cathode and also the SEEA development, we tend to changed the electrode geometry like thickness of alumina ceramics and tip radius of cathode rod, respectively, and put in a plane electrode as the rear electrode of the cathode rod. Because the results, EEE current was reduced by the sector relaxation result of transient charging thanks to EEE, and SEEA was conjointly suppressed by the perpendicular electrical field of the plane electrode. When the flashover was suppressed by using the cathode back electrode, transient charge quantity was smaller on alumina dielectrics at the top of the plane electrode space. From the on top of results, it might be a good technique for the control and suppression of surface flashover in vacuum to enlarge the perpendicular electric field for the insulator.