Transmission Line System Modeling and Lightning Transient Response Analysis

In order to analyze the lightning wave refraction and reflection process of a typical 110kV transmission line and accurately calculate its lightning protection level, it is particularly important to establish a joint transient analysis model of the transmission line, tower and grounding device. Therefore, the integrated model of transmission line, tower and grounding device is built in EMTP in this paper. In particular, considering the wave process of the nominal height part, the call height is divided into 4 sections for modeling. In addition, a transient circuit model considering spark effect of grounding device is established. Finally, the simulation results show that the refined modeling of the nominal height part will highlight the reflection process of the lightning wave in the tower. Considering the model of spark effect, the impact characteristics of grounding device can be shown. Lightning current waveform has a significant impact on the lightning wave process, and the shorter the wave front time is, the higher the top potential is. The model established in this paper can provide simulation and theoretical basis for lightning protection of transmission lines.