Research on three-dimensional development simulation modeling method of lightning channel based on simulated charge method

The development model of the lightning channel is the basis for studying the distribution of ground lightning density. The existing lightning channel simulation model is based on two-dimensional model, and the electric field strength distribution in space is calculated by the simulation charge method, so as to simulate the development process of lightning channel. However, the actual lightning channel condition is a three-dimensional structure, and the two-dimensional model cannot truly reflect the impact of the three-dimensional environment on the lightning channel. For this reason, it is necessary to study the three-dimensional development simulation modeling method of the lightning channel. This paper proposes the development model of lightning channel with 17 degrees of freedom in the first place. Based on the development direction and inclination of these 17 free leaders, the calculation formulas of the electric field intensity of the three-dimensional space pilot head are deduced. In this paper, the simulated charge method is used for calculation, and it is found that the transition condition will reach at the initial stage of lightning process when the lightning channel is too high. Because the development direction of lightning has a strong probability characteristic, which is very obvious in three-dimensional space. As a result, lightning could breakdown at higher altitudes. In this paper, by studying the viaducts of different heights and the initial lightning displacement in different directions, it is proposed that the increase in the viaduct height will increase the lightning stroke rate of the catenary system; the initial lightning displacements in different directions will make the left and right space field imbalance and the effect is enhanced to increase the lightning stroke rate on the offset side. Finally, by changing the initial position of the lightning channel, this paper limits the influence of the height of the lightning channel on the electric field to a certain range, and proposes a three-dimensional development simulation modeling method of the lightning channel.