scholarly journals Research on the Influence of Typical Soil Parameters on Critical Breakdown Field Strength and Residual Resistivity Based on Discharge Topography

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4810
Author(s):  
Donghui Luo ◽  
Jialun Li ◽  
Yongxing Cao ◽  
Bo Tan ◽  
Wei Li ◽  
...  
Keyword(s):  
Field Strength ◽  
Discharge Channel ◽  
Partial Discharge ◽  
Residual Resistivity ◽  
Breakdown Field ◽  
Soil Parameters ◽  
Sand Soil ◽  
Cinnamon Soil ◽  
Breakdown Field Strength ◽  
Typical Soil

Partial discharge of soil occurs when a lightning current enters the ground, and the strength of partial discharge is closely related to the magnitude of its critical breakdown field strength. Therefore, how to accurately obtain the variation law of the typical soil critical breakdown field strength and residual resistivity is the key to realizing the safe operation of the grounding devices and cables in the ground. This paper first selects a variety of typical soils to study the influence of various factors on the morphology of the discharge channel, and then studies the calculation methods of the soil critical breakdown field strength and residual resistivity under the introduction of different discharge channel morphologies and structures, and further discusses the reason why typical soil media factors have a small impact on the critical breakdown field. The experimental results show that under the same conditions, the critical breakdown field strengths of different soils from small to large are sand soil, loam soil and Yellow cinnamon soil. The largest ratio of residual resistivity to initial resistivity of the three soils is sand soil.

scholarly journals Effect of Acetylated SEBS/PP for Potential HVDC Cable Insulation

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1596
Author(s):  
Peng Zhang ◽  
Yongqi Zhang ◽  
Xuan Wang ◽  
Jiaming Yang ◽  
Wenbin Han
Keyword(s):  
Mechanical Properties ◽  
Field Strength ◽  
Thermoplastic Elastomer ◽  
High Energy ◽  
Thermoplastic Elastomers ◽  
Electrical Strength ◽  
Voltage Stabilizer ◽  
Breakdown Field ◽  
Cable Insulation ◽  
Breakdown Field Strength

Blending thermoplastic elastomers into polypropylene (PP) can make it have great potential for high-voltage direct current (HVDC) cable insulation by improving its toughness. However, when a large amount of thermoplastic elastomer is blended, the electrical strength of PP will be decreased consequently, which cannot meet the electrical requirements of HVDC cables. To solve this problem, in this paper, the inherent structure of thermoplastic elastomer SEBS was used to construct acetophenone structural units on its benzene ring through Friedel–Crafts acylation, making it a voltage stabilizer that can enhance the electrical strength of the polymer. The DC electrical insulation properties and mechanical properties of acetylated SEBS (Ac-SEBS)/PP were investigated in this paper. The results showed that by doping 30% Ac-SEBS into PP, the acetophenone structural unit on Ac-SEBS remarkably increased the DC breakdown field strength of SEBS/PP by absorbing high-energy electrons. When the degree of acetylation reached 4.6%, the DC breakdown field strength of Ac-SEBS/ PP increased by 22.4% and was a little higher than that of PP. Ac-SEBS, with high electron affinity, is also able to reduce carrier mobility through electron capture, resulting in lower conductivity currents in SEBS/PP and suppressing space charge accumulation to a certain extent, which enhances the insulation properties. Besides, the highly flexible Ac-SEBS can maintain the toughening effect of SEBS, resulting in a remarkable increase in the tensile strength and elongation at the break of PP. Therefore, Ac-SEBS/PP blends possess excellent insulation properties and mechanical properties simultaneously, which are promising as insulation materials for HVDC cables.

Electrical Properties of a TiO2-SrO Varistor System

2014 ◽  
Vol 975 ◽  
pp. 168-172
Author(s):  
Tiago Delbrücke ◽  
Igor Schmidt ◽  
Sergio Cava ◽  
Vânia Caldas Sousa
Keyword(s):  
Titanium Dioxide ◽  
Electrical Properties ◽  
Field Strength ◽  
Leakage Current ◽  
Low Voltage ◽  
Nonlinear Coefficient ◽  
Breakdown Field ◽  
Strontium Oxide ◽  
Breakdown Field Strength

The addition of different dopants affects the densification and electrical properties of TiO2 based varistor ceramics. The nonlinear current (I) and voltage (V) characteristics of titanium dioxide are examined when doped with small quantities (0.5-2 at.%) of strontium oxide. This paper discusses the electrical properties of such an SrO doped TiO2 system, and demonstrates that some combinations produce electrical properties suitable for use as low voltage varistors. The high value of the nonlinear coefficient (α) (6.6), the breakdown field strength (Eb) (328 V/cm) and the leakage current (Ir) (0.22 mA/cm2) obtained in a system newly doped with SrO, are all adequate properties for application in low voltage varistors.

Excellent energy storage density and efficiency in lead-free Sm-doped BaTiO3–Bi(Mg0.5Ti0.5)O3 ceramics

2020 ◽  
Vol 8 (38) ◽  
pp. 13405-13414
Author(s):  
Zhi-Gang Liu ◽  
Zhen-Hua Tang ◽  
Song-Cheng Hu ◽  
Di-Jie Yao ◽  
Fei Sun ◽  
...  
Keyword(s):  
Energy Storage ◽  
Field Strength ◽  
Oxygen Vacancies ◽  
Lead Free ◽  
Breakdown Field ◽  
Energy Storage Density ◽  
Storage Density ◽  
Breakdown Field Strength

Doping decreased oxygen vacancies in ceramics, resulting in high breakdown field strength and excellent energy storage performances.

Insulation Treatment of 2A12 Aluminum Alloy Surface by Plasma Electrochemical Oxidation

2011 ◽  
Vol 687 ◽  
pp. 297-302
Author(s):  
Ming Liu ◽  
Zhi Hua Sun ◽  
Zhi Shen Wang ◽  
Xiao Yun Zhang ◽  
Feng Lu
Keyword(s):  
Aluminum Alloy ◽  
Field Strength ◽  
Electrochemical Oxidation ◽  
Alloy Surface ◽  
Breakdown Field ◽  
Electric Resistance ◽  
X Ray Diffraction ◽  
Peo Coatings ◽  
Aluminum Alloy Surface ◽  
Breakdown Field Strength

The 2A12 aluminum alloy surface is treated by plasma electrochemical oxidation (PEO) in alkaline solution. X-ray Diffraction (XRD) is used to analyze the phases of PEO coatings. Scanning Electron Micrograph (SEM) is used to investigate the compactness of PEO coatings. High resistance meter and voltage resistance meter are used to measured Electric resistance and breakdown field strength of PEO coatings respectively. The results show that the PEO coating is composed of α-Al2O3, γ-Al2O3 , etc, and they are all well-insulated substance which is profitable to insulation of 2A12 aluminum alloy. When the thickness of PEO is more than 60μm, porosity in the PEO coating is estimated not more than 15%. Electric resistivity of PEO coatings can reach as high as 1013 Ω·cm, and breakdown field strength of the PEO coatings can reach 72 V / μm.

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