The effect of temperature cycles on conductivity mechanism using polyimide

Qin, Sichen; Tu, Youping; Chen, Bingying; Xu, Duohu; Tan, Tian; Chen, Geng; Yuan, Zhikang

doi:10.1063/5.0027017

Cited by 7 publications

(6 citation statements)

References 32 publications

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“…3,35,36 In addition, for polymer dielectrics, the trap localized states are mainly distributed in the amorphous region. [37][38][39] Therefore, microscopic moisture adsorption in the amorphous region and its effect on trap localized states were explored by MD simulations and QC calculations, respectively.…”

Section: A Computational Detailsmentioning

confidence: 99%

Mechanism study of the conductivity characteristics of cellulose electrical insulation influenced by moisture

Zhao

Zhang

et al. 2022

Journal of Applied Physics

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Cellulose insulating paper is widely used in the power industry for its good electrical insulating properties. Moisture sharply increases its conductivity, which directly leads to the weakening of insulation performance and greatly increases the risk of subsequent electric field distortion and insulation breakdown. This paper focuses on the microscopic mechanism of moisture changing the characteristics of charge transport in cellulose insulation and attempts to reveal the related conductivity mechanism. To achieve this purpose, microscopic and macroscopic perspectives are integrated and several simulation and experimental methods are utilized comprehensively. The molecular dynamics simulation results showed that most water molecules in damped cellulose were individually and uniformly adsorbed on the hydroxyl groups by hydrogen bond, and the quantum chemistry computation results showed that the lowest unoccupied molecular orbital more appeared on the water molecule and the corresponding density of state increased. Then, experimentally, it was confirmed that the trap energy level decreased by the thermally stimulated current method. On this basis, the promotion effect of moisture on charge transport is predicted and verified by polarization and depolarization current methods. As the moisture content increased, more charge carriers escaped from the trap by hopping and participated in long-range continuous charge motion. Therefore, after dampness, the current of cellulose insulating paper increased exponentially with the increase in electric field strength, which was consistent with the hopping conductivity mechanism.

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Section: A Computational Detailsmentioning

confidence: 99%

Mechanism study of the conductivity characteristics of cellulose electrical insulation influenced by moisture

Zhao

Zhang

et al. 2022

Journal of Applied Physics

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“…The conductivity value of a solid dielectric is not a constant value, but a dynamic value dominated by the temperature and electric field. 13) This is because the trap capture processes make the conductivity value decreased with time and the trap escape process makes the conductivity value increased with the temperature and electric field. 14,15) Hence, the effect of traps on conductivity value should be considered.…”

Section: Simulation Modelmentioning

confidence: 99%

Simulation study on the electric field of HVDC-GIL based on the dynamic conductivity model subjected to different current-carrying capacities

Qin

Wang

et al. 2021

Jpn. J. Appl. Phys.

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In this paper, we propose a thermal-electric coupling model based on the dynamic conductivity model, which considering the charge-trapping process. The charge accumulation characteristic under different current-carrying capacities was also investigated. The saturation time of average charge density and the average temperature in the space are approximate, which could be concluded that the charge accumulation is accompanied by the establishment of a temperature field. When the current-carrying capacity reaches 3000 A, the maximum surface electric field of the basin insulator will continue to rise 14.2% compared with 1500 A. The charge migration and accumulation near the enclosure results in a greatly distorted electric field near the triple junction of the ground enclosure. This paper could offer theoretical insights from a dielectric charge transport theory and perspective to be helpful for the design of spacer in HVDC-GIL.

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“…A distribution model of carbon black particles in PDMS after ion implantation is also presented. More importantly, these methods can support the development of electrodes in other areas of dielectrics [ 33 , 34 , 35 ] and research [ 36 , 37 , 38 ]. This work has potential value for the design of new flexible electrodes and composite conductive functional materials.…”

Section: Introductionmentioning

confidence: 99%

Study of a Mixed Conductive Layer Fabricated by Ion Implantation and Distribution Theory

et al. 2023

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Electrodes are essential parts of capacitors that can consist of a variety of materials depending on the application. In dielectric elastomer transducers (DETs)—a type of special variable capacitor—the electrode needs to deform with a soft base. However, the current carbon-based electrodes are not stable, and the metal-based ones are not flexible for use in DETs. Thus, the need to fabricate an electrode which can meet both the stability and flexibility requirements is extremely important. In this work, silver ions with energy levels of 40 keV were implanted into the surface of polydimethylsiloxane (PDMS) to explore the effect of ion implantation on surface conductivity. The experimental results showed that the surface resistivity of PDMS reached 251.85 kΩ per square and dropped by 10 orders of magnitude after ion implantation. This indicates that the surface conductivity was significantly improved. EDS characterization results showed that the maximum penetration depth that ions could reach was about 2.5 μm. The surface resistivity of the sample coated with carbon black was further reduced by an order of magnitude after ion implantation and changed more stably with time. A quasi-melting-collision model was established to investigate the distribution of carbon black particles. The concentration of carbon black particles at a distance from the PDMS surface followed a Gaussian-like distribution.

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The effect of temperature cycles on conductivity mechanism using polyimide

Cited by 7 publications

References 32 publications

Mechanism study of the conductivity characteristics of cellulose electrical insulation influenced by moisture

Mechanism study of the conductivity characteristics of cellulose electrical insulation influenced by moisture

Simulation study on the electric field of HVDC-GIL based on the dynamic conductivity model subjected to different current-carrying capacities

Study of a Mixed Conductive Layer Fabricated by Ion Implantation and Distribution Theory

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