scholarly journals Analysis on the Influence of Transmission Lines span on Passive Interference in Shortwave

2018 ◽  
Vol 64 ◽  
pp. 05004
Author(s):  
Ying Lu ◽  
Zhibin Zhao ◽  
Jian gong Zhang ◽  
Zheyuan Gan
Keyword(s):  
Electromagnetic Field ◽  
Transmission Line ◽  
Transmission Lines ◽  
Electromagnetic Scattering ◽  
Electromagnetic Waves ◽  
Short Wave ◽  
Critical Distance ◽  
Observation Point ◽  
Radio Station ◽  
Passive Interference

The passive interference of transmission lines to nearby radio stations may affect the effective reception and transmission of radio station signals. Therefore, the accurate calculation of the electromagnetic scattering of transmission lines under the condition of external electromagnetic waves is the basis for determining the reasonable avoidance spacing of the two. For passive stations operating in short-wave frequencies, passive interference is mainly generated by the tower, and span is one of the most significant factors affecting passive interference. This paper uses the method of moments to carry out the passive interference calculations under normal circumstances, expounds the method of calculating the electromagnetic field of transmission line at the same time. And elaborates the method for calculating the electromagnetic field of the transmission line, obtains the space electric field intensity of the transmission line at the same working frequency and space location of the plane wave. Applying the approximate formula to calculate the formula for the span and critical distance between the observation point and the transmission line.

scholarly journals Analysis on the Influence of the Height of Tower on Passive Interference in shortwave

2018 ◽  
Vol 64 ◽  
pp. 05005
Author(s):  
Ying Lu ◽  
Zhibin Zhao ◽  
Jian gong Zhang ◽  
Zheyuan Gan
Keyword(s):  
Transmission Line ◽  
Method Of Moments ◽  
Transmission Lines ◽  
Electromagnetic Scattering ◽  
Electromagnetic Waves ◽  
Short Wave ◽  
Radio Station ◽  
Radio Stations ◽  
Working Frequency ◽  
Passive Interference

The passive interference of transmission lines to nearby radio stations may affect the effective reception and transmission of radio station signals. Therefore, the accurate calculation of the electromagnetic scattering of transmission lines under the condition of external electromagnetic waves is the basis for determining the reasonable avoidance spacing of the two. For passive stations operating in short-wave frequencies, passive interference is mainly generated by the tower. This paper uses the method of moments to perform passive interference calculations under normal circumstances, And elaborates the method for calculating the electromagnetic field of the transmission line, obtains the space electric field intensity of the transmission line at the same working frequency and space location of the plane wave. Uses the approximate formula to inductive the formula for calculating height of tower and the protective distance.

scholarly journals Influence of Transmission Line Pitch on Passive Interference

2018 ◽  
Vol 64 ◽  
pp. 05006
Author(s):  
Ying Lu ◽  
Jian gong Zhang ◽  
Zheyuan Gan ◽  
Zhibin Zhao
Keyword(s):  
Transmission Lines ◽  
Electromagnetic Scattering ◽  
Moment Method ◽  
Electromagnetic Waves ◽  
Radio Station ◽  
Radio Stations ◽  
Overhead Lines ◽  
Passive Interference ◽  
Save Energy ◽  
Main Factor

Passive interference of transmission lines to neighbouring radio stations may affect the effective reception and transmission of radio station signals. Therefore, it is the basis to accurately calculate the electromagnetic scattering of transmission lines including overhead wires and towers under the circumstance of electromagnetic waves from outside. Wherein for radio stations, the overhead conductor is the main factor that affects the radar detection because of the working mode of the radar and other factors. In this paper, in the general case of the application of moment method to carry out passive interference calculations, the overhead lines are assumed to be all the actual wire. The space electric field strength and RCS of the different pitch at different operating frequencies and spaces are obtained. The influence of pitch on passive interference of overhead conductors was analyzed. Thus providing a basis for modeling to save energy and reduce the effects of passive interference provides the modeling basis.

Research on Frequency Electromagnetic Field of Parallel Transmission Line

2014 ◽  
Vol 986-987 ◽  
pp. 1992-1995
Author(s):  
Hong Ying Cao ◽  
Bo Tang ◽  
You Xian Peng ◽  
Yu Li ◽  
Bin Chen
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Transmission Line ◽  
Transmission Lines ◽  
The State ◽  
National Standards ◽  
Power Lines ◽  
Three Gorges ◽  
Parallel Transmission ◽  
Electric And Magnetic Field

At present the study mainly for frequency electromagnetic field which is based on a single transmission line meanwhile the value must be in line with the requirements of the workers in the country frequency electromagnetic field. However, for parallel transmission line the maximum of frequency electromagnetic field is still to meet the provisions of the state, therefore in this paper studied the parallel transmission lines. Taking the multiple parallel power lines of China Three Gorges University as an example, the values of electric and magnetic field are calculated and the electromagnetic field is measured based on National standards. Then, compare the measured value with theoretical value, verified the correctness of the superposition algorithm.

Consider the nonuniformity of the electromagnetic field when calibrating thin dipole and loop antennas in electromagnetic field source based on a four-wire transmission line

Metrologiya ◽  
2021 ◽  
pp. 60-74
Author(s):  
V. I. Lukyanov ◽  
M. V. Vasilyeva
Keyword(s):  
Electromagnetic Field ◽  
Transmission Line ◽  
Transmission Lines ◽  
Field Source ◽  
Electric And Magnetic Fields ◽  
Field Uniformity ◽  
Approximation Formulas ◽  
Infinite Line ◽  
Calibration Accuracy ◽  
Loop Antennas

The influence of nonuniformity of electric and magnetic fields on the calibration accuracy of dipole and loop antennas in field sources based on four-wire transmission lines is theoretically investigated. The paper proposes to take into account the influence of the nonuniformity of the electromagnetic field of a four-wire source when calibrating thin dipole and loop antennas using the equivalence coefficients. The use of these coefficients, taking into account the distributions of the field in the source and the current on the antenna conductors, can significantly weaken the requirement for field uniformity when calibrating antennas. For some common types of antennas, formulas are derived for the equivalence coefficients in the approximation of a four-wire source by an infinite line. Approximation formulas, simplified for engineering calculations, are obtained.

Research on Electromagnetic Environment of Transmission Line

2014 ◽  
Vol 1022 ◽  
pp. 165-168
Author(s):  
Pei Lin Li ◽  
Si Qi Lv ◽  
Tian Le Li
Keyword(s):  
Electromagnetic Field ◽  
Transmission Line ◽  
Environmental Protection ◽  
Transmission Lines ◽  
Calculation Method ◽  
Power Transmission ◽  
Social Awareness ◽  
Electromagnetic Environment ◽  
Power Frequency

With the increasing development of China's power transmission project and social awareness of environmental protection, the problem of electromagnetic environment of transmission line has been widely concerned. This paper studies the electromagnetic environment around the transmission lines, analyzes the calculation method of power frequency electromagnetic field and the measures to reduce the power frequency electromagnetic field.

scholarly journals Variations in Velocity and Sensitivity of Electromagnetic Waves in Transmission Lines Configured in Model Piles with Necking Defects Containing Soils

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6541
Author(s):  
Jung-Doung Yu ◽  
Sang Yeob Kim ◽  
Jong-Sub Lee
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Time Domain ◽  
Electromagnetic Waves ◽  
Electrical Wire ◽  
Different Types ◽  
Bored Piles ◽  
Time Domain Reflectometer ◽  
Water Contents ◽  
Soil Water Contents

This study investigates variations in the velocity and sensitivity of electromagnetic waves in transmission lines configured in defective model piles for the detection of necking defects containing soil. Experiments are performed with model piles containing defects filled with different materials, such as air, sands, and clay. Five different types of transmission lines are configured in model piles. The electromagnetic waves are generated and detected using a time domain reflectometer. The velocity of electromagnetic waves is highest when the defect is filled with air, and it decreases with an increase in the water content. The velocity is lowest when the defect is filled with clay. The sensitivity of transmission lines for detecting defects decreases with an increase in soil water contents. The transmission line with a single electrical wire and epoxy-coated rebar exhibits the highest sensitivity, followed by that with three and two parallel electrical wires. Transmission lines with a single electrical wire and uncoated rebar and those with two parallel electrical wires wrapped with a sheath exhibit poor sensitivity when the defect is filled with clay. This study demonstrates that electromagnetic waves can be effective tools for detecting necking defects with wet and conductive soils in bored piles.

scholarly journals Analysis of passive interference on radio station from AC UHV power

2018 ◽  
Vol 64 ◽  
pp. 05002
Author(s):  
Zheyuan GAN ◽  
Jiangong ZHANG ◽  
Jun ZHAO ◽  
ying Lu
Keyword(s):  
Transmission Lines ◽  
Electromagnetic Interference ◽  
Detection Performance ◽  
Radio Station ◽  
Secondary Radiation ◽  
Surface Reflection ◽  
Shadowing Effect ◽  
Passive Interference ◽  
Uhv Transmission Lines

The problems of Electromagnetic Interference in Airborne Intelligence Radar Stations near the AC UHV Transmission Lines is researched in this paper, which is mainly passive interference. And then analyzed the passive interference of AC UHV lines. It mainly studied the influence of the tower and line on the distance detection performance of the air-to-air intelligence radar of the UHV transmission lines. and integrated the influence of the surface reflection surface, the shadowing effect and the secondary radiation echo interference, Proposed a passive interference protection distance for UHV transmission lines and airborne intelligence radar stations

Electromagnetic Scattering: The Mie Solution

2017 ◽  
Author(s):  
John A. Adam
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Electromagnetic Wave ◽  
Electric Field ◽  
Electromagnetic Scattering ◽  
Scattered Radiation ◽  
Electromagnetic Waves ◽  
Rayleigh Scattering ◽  
Electromagnetic Theory ◽  
Electromagnetic Energy

This chapter focuses on the mathematics underlying the scattering of electromagnetic waves. An electromagnetic wave is comprised of an electric field and a magnetic field, both of which are functions of time and space as the wave propagates. The direction of propagation and the directions of these fields form a mutually orthogonal triad. When an electromagnetic field encounters an electron bound to a molecule, the electron is accelerated by the electric field of the wave. An accelerated electron will also radiate electromagnetic energy in the form of waves in all directions (to some extent)—this is known as scattered radiation. The chapter first considers Maxwell's equations of electromagnetic theory before discussing the vector Helmholtz equation for electromagnetic waves, the Lorentz-Mie solution and its construction, the Rayleigh scattering limit, and the radiation field generated by a Hertzian dipole.

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