The Study On The Lightning Prevention Design Of370m Tower Used In The Large Crossing Of Zhoushan

In Zhoushan and the mainland electric network interconnection project,370m crossing tower will be used at Luotou channel large crossing,it will become the highest electric transmission line tower in the world, and the probability of lightning striking is increased with the height increased. The designers must take necessary measures to avoid the large crossing tower being the weakest spot of the lightning prevention of the whole transmission line, and make sure the long safe operation and fulfill operation department’s requirement of.lightning striking trip-out rate. Based on the research of the lightning flashover and lightning prevention design of the large crossing high tower at home and abroad, analyssing the calculation method of the lightning trip-out rate of the transmission line, finally,we use EMTP and electric geometry model to calculate and analyse the counterattack and shielding failure rate of the high tower in Luotou channel large crossing, the gap on the external over-voltage is also studied in this paper. By analyzing the usual lightning prevention measures used in large crossing tower and combining with the actual situation of this project, we suggest that lightning arrester and reinforced insulation design should be adopted in lightning prevention in order to increase the lightning striking withstand level.