The charge distribution in lightning downward leader channel based on RC distributed circuit model

As the premise of the simulation of the lightning leader development process, it is crucial to establish a charge distribution model of the lightning channel. However, all the existing models are not fully demonstrated physically, and further research is necessary. This paper presents significant differences between the charge distributions derived from the existing models and those derived from the field measurements. Then, a parallel RC circuit model is proposed, equivalent to the leader development process at the steady-state stage. When the lightning leader goes down, variation rules of self-capacitances, mutual capacitances, and resistance can be obtained and explained through this model. An ATP-EMTP model composed of these elements is constructed to simulate the development of lightning leaders, and the voltage of each self-capacitance is acquired by simulation. Then, the charge of each segment of the channel is obtained. Finally, the simulation results are compared to those derived from the measured electric field to validate that they have a similar distribution. The research in this paper can provide a foundation for further lightning strike path simulations, lightning distribution prediction, and so on.