Research on Insulation Level and Lightning Protections of 10 kV Overhead Insulated Distribution Lines

摘要

The operation data of the distribution line in the mountainous area indicates that the lightning stroke of the 10kV insulated wire has occurred frequently. Since the insulation level of the distribution line is low, once the phase-to-phase flashover is triggered, the arc root is blocked by the insulation of the line, and it cannot move along the surface of the conductor to cause the wire to fuse at high temperature. This paper analyzes the breaking mechanism of typical 10kV insulated wire, the overvoltage induced by lightning is calculated and the lightning impulse withstand voltage of 10kV insulated wire is obtained through the experiments. On this basis, the lightning protection method of improving the line insulation level by using the combination of insulator and composite insulated crossarm is put forward. At the same time, the addition of silicone rubber insulation sheath on the crossarm surface can significantly improve the pollution flashover insulation level of the line. The impulse insulation level of 80cm length non-sheds composite insulation cross arm can reach 383kV, and the impulse insulation level of 60cm length composite insulated crossarm with sheds can reach 403kV, meeting the lightning protection requirements of 10kV lines in severe pollution areas.