A research on discharge phenomena and mechanism of the suspended needle

The influences of the two kinds of floating conductor defects, plate-needle-plate and needle-needle-plate, on the partial discharge are investigated. For the plate-needle-plate structure, the discharge is initiated from the suspended needle conductor, and two kinds of discharges, corona and partial breakdown, are produced separately at different half cycle of the applied voltage, but both are formed on the rising front of the voltage. Its mechanism is almost the same as that of the dielectric barrier discharge (DBD), the charge accumulated on the suspended conductor inhibits the subsequent discharge, but activates the discharge in the next half-cycle. For the needle-needle-plate structure, the partial breakdown is produced on the rising front of voltage when the applied voltage is low; the partial breakdown and the subsequent corona are produced on the rising front of voltage when the applied voltage is high. Its mechanism is also the same as DBD. It means that the magnitude of the accumulated charge and its polarity are the key factors for the discharge of the suspended conductor.