Solution and Analysis of Scattering Field of Power Transmission Lines Based on Characteristic Mode Theory

Abstract

Solving the scattering field of power transmission lines and analyzing its scattering characteristics are essential for suppressing the reradiation interference from power transmission lines on neighboring radio stations. However, traditional methods based on the method of moments (MoM) cannot analyze the relationship among the external excitation, power transmission line structure and scattering field, making it difficult to put forward targeted interference suppression measures. In this study, a method based on the characteristic mode (CM) theory is proposed for the analysis of scattering characteristics. Firstly, a generalized eigenvalue equation for solving the inherent current distribution on the metal surface of the power transmission line is established; Secondly, combined with the electric field integral equation (EFIE), the CM parameters used for mode decomposition are calculated to measure the relationship between the external excitation and the CM; Finally, the scattering field of the power transmission lines is approximately expressed as the vector superposition of the characteristic electric fields. Simulation experiments are carried out in medium-wave and short-wave bands. The simulation results show that significant CMs can account for the scattering field in the frequency band, and the average absolute error of the scattering field and the maximum relative error of scattering field extreme value will not exceed 0.83 mV/m and 2.84%, respectively.

Keywords

• Power transmission lines
• reradiation interference
• characteristic mode theory
• scattering field
• eigenvalue equation