Research On The Numerical Method Of Radio Interference Of HVAC Transmission Lines

With the increasing use of high voltage transmission lines, the electromagnetic pollution caused by corona discharge is becoming a serious problem. One of the most important electromagnetic effects of corona activity of the transmission line is the radio interference. Prediction of the radio interference caused by corona is of great importance for the design of the transmission network.At present, the calculation method of the radio interference basically have two kinds, one kind is the empirical formula method; the other is excitation function method. The application scope of two methods is different. The experience formula method is suitable for the lines that conductor division number is less than4lines, while the excitation function is suitable for the lines that the conductor dividing numbers is greater than4. The two methods are based on a large amount of experimental data by summing up the formula; the application of these two methods will meet the experimental constraints.With the different of the two methods, this paper presents the numerical calculation method of radio interference calculation. The method came from the essence theory, by analysis of the corona generation mechanism of transmission line, and with the charge simulation method to calculate the corona current and radio interference. This paper also calculated some examples with experience formula and the excitation function method for comparison and verification.This paper studied the factors which affected the radio interference of the numerical calculation method, such as line height, number of sub-conductors, conductor radius, conductor bundle spacing, soil resistivity, conductor roughness coefficient and so on.