Effects of Surface Charges on Hydrophobicity and Surface Potential Decay with Various Surface States of Silicone Rubber for Outdoor Insulator

<p>Accumulation of interfacial charges is an inherent feature of HVDC insulation based on solid and gaseous media. The collected surface charges can alter the geometrical electric field leading to undesirable phenomena such as partial discharges and even unexpected flashovers. <br />In the present paper, surface potential decay on silicone rubber samples is analyzed at reduced pressures of ambient air that allows for elimination of surface charge neutralization by gas ions. Thus, influences imposed by bulk and surface conduction in the solid material are studied by means of computer simulations and experimental measurements. The results allow for identifying levels of bulk and surface conductivities above which the corresponding charge decay mechanism becomes dominant. It is shown that with a negligible space charge effect and significant surface leakage, there exists a notable spread of charge along gas-solid interface yielding visible crossover phenomenon in charge decay characteristics. It is also demonstrated that the effect of space charge in the material bulk on surface potential decay can only be significant within layers of material finer than ca. 100 μm.</p>

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Analysis of Surface Potential Decay and Charge Trap Characteristics of Water Diffused Silicone Rubber Nanocomposites

2021 IEEE International Conference on the Properties and Applications of Dielectric Materials (ICPADM) ◽

10.1109/icpadm49635.2021.9494001 ◽

2021 ◽

Author(s):

B Thangabalan ◽

Janjanam Naveen ◽

Michael. G. Danikas ◽

Ramanujam Sarathi

Keyword(s):

Surface Potential ◽

Silicone Rubber ◽

Charge Trap ◽

Potential Decay ◽

Rubber Nanocomposites

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Effect of Aging under AC Superimposed Harmonic Voltage on Trap and Carrier Transport Properties of Silicone Rubber

Applied Sciences ◽

10.3390/app10176006 ◽

2020 ◽

Vol 10 (17) ◽

pp. 6006

Author(s):

Jiachi Yao ◽

Qingzhou Wu ◽

Haozhe Cui ◽

Guowei Zhang ◽

Guanghao Qu ◽

...

Keyword(s):

Electrical Conductivity ◽

Dielectric Loss ◽

Power System ◽

Aging Time ◽

Surface Potential ◽

Silicone Rubber ◽

Experimental Results ◽

Low Frequencies ◽

Potential Decay ◽

Electron And Hole Traps

The rapid growth of power grid capacity and the widespread use of a large number of power electronics and non-linear loads have led to harmonics in the power system. Harmonics in the power system will cause safety hazards to the normal operation of power equipment, exacerbate the aging of insulation materials, and reducing the overall operation reliability of the system. In the present work, we used power frequency ac voltage superimposed harmonics to carry out ageing experiments on power cable terminals. Then, we tested the infrared spectra, dielectric spectra, electrical conductivity, and surface potential decay characteristics of silicone rubber insulation materials on the cable terminals aged for different times. The experimental results show that the dielectric constant and dielectric loss of silicone rubber gradually increase with the aging time. In particular, the dielectric loss of silicone rubber changed greatly at low frequencies. The effect of dc conductance of aged silicone rubber on dielectric loss is significantly enhanced at low frequencies, which causes the dielectric loss to increase as the frequency decreases following an inverse power law. The surface potential decay rates of silicone rubber insulation after positive and negative corona charging accelerate with increasing the aging time, which is consistent with the experimental results of electrical conductivity. By analyzing the distribution characteristics of electron and hole traps in silicone rubbers, it is found that the trap energy levels of electron and hole traps become shallower as the operating time increases. The calculation of the carrier hopping conduction model shows that the shallow trap formed with increasing the aging time will lead to increases in both carrier mobility and conductivity. When the conductivity rises to a certain value, the silicone rubber will lose its insulation performance, resulting in insulation failure.

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Investigation of Surface Potential Decay Behavior of Insulator Polymers after High-Voltage Poling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1042.245 ◽

2014 ◽

Vol 1042 ◽

pp. 245-248

Author(s):

Jia Wei Zhang ◽

Rabah Belouadah

Keyword(s):

Polyvinyl Chloride ◽

Surface Potential ◽

High Voltage ◽

Cellular Structure ◽

Charge Storage ◽

Surface Charges ◽

Storage Mechanism ◽

Charge Storage Mechanism ◽

Potential Decay ◽

Decay Behavior

In order to investigate the surface potential decay tendency of the insulator polymers such as Polypropylene (PP) and Polyvinyl Chloride (PVC), the high voltage corona triode was applied to inject the charge into the surface and volume of the samples. Due to that the surface potential decay tendency is of utmost important to the investigation of space charge storage mechanism in those polymers, the decay tendency of each sample was tested and observed. The results show that the polypropylene with cellular structure can stored larger amount of the surface charges than the polyvinyl chloride. The results could be put into industrial application of insulation materials in the related fields of electrical insulation engineering.

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