scholarly journals Helix grounding electrode with good grounding performance

2019 ◽  
Vol 277 ◽  
pp. 03007 ◽  
Author(s):  
Zhanlong Zhang ◽  
Yihua Dan ◽  
Daojun Mei ◽  
Jing Zou ◽  
Peiyu Jiang
Keyword(s):  
Surface Potential ◽  
Surface Current ◽  
Current Density Distribution ◽  
Electrical Equipment ◽  
Installation Space ◽  
Stable Operation ◽  
Surface Current Density ◽  
Grounding Resistance ◽  
Step Voltage ◽  
Grounding Electrode

Grounding electrode is used for discharging current and ensure the safe and stable operation of electrical equipment. Grounding performance of grounding electrode will degradation with limited installation space. This paper proposes helix grounding electrode and builds theoretically and simulating model on the helix grounding electrode. Analyzing grounding surface potential and step voltage distribution, grounding resistance and surface current density distribution. Results show helix grounding electrode can reduce grounding resistance, improve grounding surface potential distribution and the discharging current distribution.

scholarly journals Electrodynamic Parameters of a Coaxial Cable at Bipolar Pulses Propagation

2020 ◽  
pp. 25-37
Author(s):  
Yanis I. Bulbik ◽  
Fedor G. Zograf
Keyword(s):  
Boundary Conditions ◽  
Density Distribution ◽  
Current Density ◽  
High Speed ◽  
Surface Current ◽  
Current Density Distribution ◽  
Coaxial Cable ◽  
Surface Current Density ◽  
Speed Increase ◽  
Outer Conductor

All-in-interworking technology, based on IEEE 802.3 standard, was mainly developed for the separable media cabling and data transmission speed increase. Although the high-speed networking is already provided by a fiber optic cable, coaxial guides are in demand for similar applications. Time-domain analysis is undertaken to estimate electrodynamic states of inner and outer guiding conductors at periodic bipolar pulses propagation on a coaxial cable. An electric current density distribution on the cross-section of the inner conductor is obtained from a solution of Maxwell equations under periodic boundary conditions that are prescribed by a product of two functions. The first one is introduced implicitly for a profile of surface current density in the axial direction, while the other determines this profile transient states. As for shielding braid, which is the cable outer conductor, its current density distribution is derived from an analysis of field harmonics that penetrate into conductive subsurface layers under similar boundary conditions. It is also shown that prescribed implicative boundary conditions for both conductors allow to obtain, at least under auxiliary assumption, some completed formulae useful to the estimation of the pulses duration admissible decrease at their transmission on the coaxial cable. The paper contains some comparative and numerical results as well

scholarly journals A new grounding model for complex soil environments

2019 ◽  
Vol 118 ◽  
pp. 03001
Author(s):  
Chong Pan ◽  
Dong Zhao ◽  
Xuesong Tu ◽  
Shuqin Wang ◽  
Tie Liu ◽  
...  
Keyword(s):  
Surface Potential ◽  
Transmission Lines ◽  
Normal Operation ◽  
Long Distance ◽  
Grounding System ◽  
Grounding Resistance ◽  
Resistance Surface ◽  
Resistance Reduction ◽  
The Common ◽  
Grounding Electrode

The purpose of arranging the grounding electrode is to discharge large currents, such as fault current and ensure the transmission line operate safely. In the grounding system of Chinese transmission network, the common grounding electrodes are horizontal installation and vertical installation. But two installation methods usually have the disadvantages, which are long distance installation and large depth burying, and they are restricted susceptible to uncertain factors such as pipelines, roads and geology, which leads the grounding resistance increasing and affect the normal operation of transmission lines. In order to solve the problem, this paper presents a new grounding model for complex soil environments and analysis from grounding resistance, surface potential and current distribution. The results show that the helix grounding electrode has good resistance reduction performance in complex soil environment, which effectively improves the surface potential distribution and the distribution of the spill current.

Single-peak-regulation and wide-angle dual-band metamaterial absorber based on hollow-cross and solid-cross resonators

2020 ◽  
Vol 91 (3) ◽  
pp. 30901
Author(s):  
Yibo Tang ◽  
Longhui He ◽  
Jianming Xu ◽  
Hailang He ◽  
Yuhan Li ◽  
...  
Keyword(s):  
Transverse Electric ◽  
Surface Current ◽  
Dielectric Substrate ◽  
Transverse Magnetic ◽  
Metamaterial Absorber ◽  
Absorption Peak ◽  
Dual Band ◽  
Single Peak ◽  
Wide Angle ◽  
Surface Current Density

A dual-band microwave metamaterial absorber with single-peak regulation and wide-angle absorption has been proposed and illustrated. The designed metamaterial absorber is consisted of hollow-cross resonators, solid-cross resonators, dielectric substrate and metallic background plane. Strong absorption peak coefficients of 99.92% and 99.55% are achieved at 8.42 and 11.31 GHz, respectively, which is basically consistent with the experimental results. Surface current density and changing material properties are employed to illustrate the absorptive mechanism. More importantly, the proposed dual-band metamaterial absorber has the adjustable property of single absorption peak and could operate well at wide incidence angles for both transverse electric (TE) and transverse magnetic (TM) waves. Research results could provide and enrich instructive guidances for realizing a single-peak-regulation and wide-angle dual-band metamaterial absorber.

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