Calculation Of The Radio Interference Of Finite AC Transmission Lines Based On Excitation Function

Injecting high voltage AC transmission lines with impedance connected to their terminals, a method for calculating the radio interference of the transmission lines with finite length is introduced. This method, combining the excitation function method with Bergeron method, can get the distribution of corona currents when the currents happen refracts and returns. And the radio interference is worked out with getting superposition of electric field produced by current elements. Variation trend of four excitation functions over different maximum conductor surface field strength and the split sub-wire radius is shown. Radio interference of infinite length wire is calculated using excitation function in the heavy rain weather and compared with the measured values. Taking the lines near transformer substations for example, the distribution characteristic of corona currents on the lines with finite length is compared to it on the lines with indefinite length. And it is proved that the radio interference of the transmission lines with finite lines are highly related to the impedance of the transformer and the location of the corona.