Analyses On Radiation And Coupling Characteristics Of Lightning Channel

In this paper,we demonstrate the radiation and coupling characteristics of lightning channel.The impulse current generated system(ICGS)was used to simulate the lightning discharge channel.A model of local thermodynamic equilibrium(LTE)is established by utilizing spectral theory and optically thin of lightning channel.And the influence on common antennas and overhead lines of lightning is analyzed,based on the antenna model of channel.We have the conclusions as below:(1)The peaks of luminous intensity of both infrared and visible spectra increase with the lightning current intensity.And the peaks of luminous intensity of infrared spectra are higher than that of visible spectra.(2)The temperature varies from 6140.7K-10424.IK when the current changes from 5kA-10kA in the lightning channel and there is a good logarithmic relationship between the temperature and the current.The fitted curve is T=1782.7lnI+3347.3,the correlation index being 98.74%.(3)It has good agreement with the relation between the current and the temperature in the natural lightning channel that the relationship between the current and the temperature in the lightning channel which was calculated by the research to the infrared spectroscopy(930 nm)and the visible spectroscopy(648.2 Un).(4)There are energy at the frequency point 315MHz.433MHz and 2.4GHz in the estimated lightning channel frequency band.Although the receiving energy of the antennas is not very high,it is high enough to influence the transmission of signal.Thus it is necessary to take effective measures to protect antennas.(5)The induced voltage of the wire increase with the augment of the load.When the load is 300ko or 680kΩ,it can be simplified to open circuit in some cases.And tiae experimental data of these two conditions have little difference with open circuit at far-end.