The flashover criterion of insulator and air gap is an important simulation model to evaluate the lightning re-sistance performance of transmission lines.The flashover criterion at different altitudes needs altitude correction.The U50%flashover criterion can be corrected by the g parameter,however,the more accurate flashover criterion,namely,us-ing the volt second characteristic and leader propagation model method,still lacks effective altitude correction.Aiming at the composite insulator used in 110 kV line and 1m rod-plate gap,we carried out the positive polarity standard lightning impulse tests in plain and high altitude areas,respectively,compared the influence of altitude on impulse flashover char-acteristics,and analyzed the problems of existing altitude correction methods in U50%and volt-second characteristic scatter correction.Then,a positive standard lightning wave leader propagation model suitable for 110 kV single compo-site insulator and 1m rod-plate gap at different altitudes was fitted,and the U-t curve calculated by the model was compared with the test volt-second characteristic,verifying the applicability of the leader propagation model to carry out the altitude correction of flashover criterion by changing the relative air density.Finally,by comparing and analyzing the effects of different leader propagation models on calculating the lightning withstand level of 110 kV transmission lines,the accuracy of altitude correction of flashover criterion of leader propagation model is verified.
关键词
长间隙/海拔校正/闪络判据/先导发展模型/耐雷水平
Key words
long air gap/altitudes correction/flashover criterion/leader propagation model/lightning withstand level
维普
万方数据