Research on Distributed-Circuit Model of the Lightning Channel Development

The existing lightning charge distribution models are mainly: 1) dipole model; 2) electric disk model; 3) exponential distribution model; 4) linear distribution model. The dipole model and the electric disk model are inferred from the ground electric field detector, and the exponential distribution and linear distribution models are inferred from the macroscopic phenomenon of lightning development. The development of lightning channels is a streamer breakdown process with stepped charge-and-discharge, so the existing lightning channel charge distribution models cannot accurately explain the development process of lightning channels. In the previously established model, it has also been verified that several models have drawbacks, and the development shape of lightning in the model is significantly different from the actual one. The distributed circuit model with resistance, capacitance, and inductance is widely used to simulate the lightning return stroke process. Now this model is applied to simulate the development process of the lightning channel, and the lightning channel is regarded as a multi-stage plasma that develops step by step. The plasma is charged-discharged-charged sequentially, and the discharge circuit is built by determining the values of resistance and capacitance. This paper proposes a new charge distribution model in the lightning channel-a stepped distribution model, in which the capacitance is calculated by the image method and the impedance is calculated by the classical analogy method. They are a function of the conductor shape, size and relative permittivity. Use EMTP software to build a circuit model and observe the voltage waveform on the distributed capacitor. According to the observed voltage waveform, it is found that the charging time of the circuit is too fast, which is quite different from the statistical data. It is thus guessed that the process of forming streamers occupies the main discharge time during the development of lightning. The model in this article does not consider in this case, this also points out the direction for the next step of research.