Lightning transient response analysis is the key to determining the lightning resistance level of transmission lines and the performance of lightning protection measures. This paper proposes a distributed modelling method for a typical 110 kV transmission tower and further analyses the lightning transient response. The refined modelling of the nominal height part of the tower is carried out. Then the influence of the refined modelling on the refraction and reflection process of the lightning wave propagation is investigated. Based on the distributed tower model, the impact of the foot distance and the equivalent radius of the main body cylinder on the top overvoltage is studied. Field experiments indicate that the proposed distributed tower model can effectively reflect the transient lightning wave process. Moreover, it can provide technical support for the lightning resistance level of transmission lines and the lightning protection of narrow base towers.

When the lightning strikes the tower, the lightning current is discharged into the ground through the tower grounding device. The magnitude of the impulse earthed resistance of the tower grounding device determines the lightning discharge capacity of the tower. Therefore, the tower grounding device directly affects the lightning protection level of the tower. This paper first introduces three commonly used shock resistance reduction methods: long vertical ground electrode, acupuncture ground electrode, and externally induced rays. Then, the CDEGS software is used to simulate and analyze the long vertical grounding electrode, and a method of insulation short shield is proposed to determine the optimal length of the vertical grounding conductor of the grounding device. Finally, the different resistance reduction effects under the change of length and number of roots are explored, and the optimal resistance reduction arrangement under the same economic conditions is realized.

No abstract

No abstract