Starting from electric field integral equation for reradiation interference calculation of transmission lines, based on the functional relationship between the induced current and the incident electric field represented by the electric field integral equation, an impedance operator associated with the structural characteristic equation of transmission line represented by the operator is constructed. Then, the method of MoM is used to discretize the generalized characteristic equation and transform it into the generalized characteristic equation represented by the system of matrix equations. Finally, the implicit restart Arnoldi method is used to achieve the numerical solution of the transmission line characteristic mode and its related parameters.

Accurately simulating and analyzing the radar echo of wind turbine(WT) blades and its Doppler characteristics is a key issue in solving the reradiation interference of wind farms to radar stations. Aiming at the problem that existing algorithms cannot accurately and in real time simulate the dynamic blade echo, based on multi view parameter estimation and fusion technology, a method of dynamic WT blade radar echo simulation based on attribute scattering center is proposed. Divide the entire rotation period of the blade 360° into multiple sub-angle domains, and based on the attribute scattering center model and greedy algorithm of orthogonal matching pursuit, the parameter set of attribute scattering center of blade is extracted, and the scattered electric field data of one rotation of blade is reconstructed. The real-time simulation and doppler characteristic analysis of dynamic blade echo are realized by using short-time Fourier transform. Taking the blades of Jinfeng 82/1500 wind turbine as an example, comparing analysis and verification with echoes obtained by traditional echo simulation algorithms, the accurate and real-time simulation of dynamic blade echoes is realized, which provides a reference for the analysis of the electromagnetic scattering characteristics of the subsequent dynamic WT and even the multi fan array in wide area space, as well as the suppression of radar side wind farm clutter.

The national standard specifies the electromagnetic field of a single line, but lacks the electromagnetic field algorithm and related regulations for parallel transmission lines (PTL). Using the electromagnetic field calculation method of transmission lines recommended by the International Conference on Large Power Grids, an algorithm for calculating the electromagnetic field strength of multiple lines in parallel is proposed using the vector superposition principle. Firstly, the algorithm is used to theoretically solve the horizontal distribution of the power frequency electric field (PFEF) and magnetic field (PFMF) of the PTL in China Three Gorges University (CTGU); then, according to the electromagnetic field measurement method stipulated by the national standard, the field measurement for the horizontal electromagnetic field distribution of the line is carried out; finally, the theoretical calculations are compared with the experimental measurements. The results show that the maximum error of the lateral distribution of the PFEF solved by the method in this paper is 0.45 kV/m, and the maximum error of the lateral distribution of the power frequency magnetic field is 0.0003 mT.

The reradiation interference from power transmission lines (PTL) on the adjacent wireless stations is directly caused by the induced current on metal parts, which means the interference could be suppressed by reducing the induced current. In order to effectively analyze the induced current of PTL, a method for analyzing induced current on PTL based on characteristic modes is proposed combining MoM with intrinsic modes. This method breaks through the traditional antenna resonance theory proposed by IEEE and could effectively avoid model equivalent defects and frequency limitations of traditional methods. Firstly, a generalized characteristic equation about the characteristic mode currents of PTL is constructed, and the numerical solutions of the characteristic mode currents are obtained by the idea of a discrete solution. Then, through the weighted orthogonal relationship between different characteristic mode currents, the expansion coefficients of the characteristic mode currents are obtained; finally, combined with the Poynting theorem, the physical meaning of the expansion coefficients and their related quantities are explained from the perspective of energy and the analysis of the induced current is realized from the physical level. The results of the example analysis show that the error between the peak frequencies of the induced current calculated by the method in this paper and the peak frequencies calculated by MoM does not exceed 2.46% and the method in this paper can well explain the disappearance of the "double wavelength loop resonance frequency" under the excitation of a vertically polarized plane wave.

Long-distance, large-capacity UHV transmission lines have increasingly become a key part of the construction of my country’s UHV power grid. However, with the increase of voltage levels, the electromagnetic interference of UHV transmission line towers to neighboring radio stations has become more and more serious, resulting in It is inevitable to study the secondary radiation suppression method of UHV transmission line towers. Therefore, based on the mechanism of suppressing the maximum value of secondary radiation, this paper proposes a secondary radiation suppression method for UHV trans- mission line towers in the mid-wave frequency band, and develops a secondary radiation suppression device based on the principle of this method. The final result shows that when the secondary radiation suppression device is not installed, the electromagnetic interference received by the measurement point is 0.4dB; after the secondary radiation suppression device is installed, the electromagnetic interference received by the measure-ment point is reduced to 0.1dB.