Nonlinear conduction and surface potential decay of epoxy/SiC nanocomposites

Han, Yongsen; Li, Shengtao; Min, Daomin

doi:10.1109/tdei.2017.006454

Cited by 40 publications

(26 citation statements)

References 35 publications

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“…This increases the charge injection barrier and weakens the interfacial electric field, resulting in less charge injection. Moreover, the distance among the fillers in EP1 is relatively large, leading to a more difficult charge hopping conduction and less accumulation in the sample bulk . For EP5, the injected charges easily move toward the opposite electrode along the overlapped interface zones due to the large filler content, contributing to less space-charge accumulation in the sample bulk .…”

Section: Experimental Results and Analysismentioning

confidence: 99%

“…EP is a typical amorphous polymer, and its DC conduction is primarily related to charge hopping over the hopping barrier Φ h . The current density J h due to the hopping conduction is represented by eq where J h0 is the hopping conduction current under a zero electric field, e is the elementary charge, λ is the average hopping distance between the potential wells, E is the electric field in the bulk of the dielectric material, k is the Boltzmann constant, and T is the temperature.…”

Section: Experimental Results and Analysismentioning

confidence: 99%

“…The power loss of the FDC materials mainly occurs in the high electric field region compared to the linear conductivity materials . However, the filler percolation threshold of FDC materials consisting of spherical fillers is usually above 10 wt %. − The excessive filler content results in poor mechanical properties and high viscosity, which is not conducive to practical applications . Nelson et al reported that the 3 wt % graphene oxide addition into poly(dimethylsiloxane) (PDMS) could achieve nonlinear conductivity with a large nonlinear coefficient of 16.…”

Section: Introductionmentioning

confidence: 99%

“…FDC composites with doped ZnO, SiC, or carbon allotrope fillers are widely used in wall bushing flanges, stator bar end of high-voltage generators, cable terminals, and gas-insulated switchgear/gas-insulated transmission line (GIL) insulators. , However, limited numbers of studies are available about their practical applications in high-voltage power modules, especially to reduce the electric field near the triple point. Through simulation, Ghassemi et al , applied FDC materials in power modules to suppress the electric field distortion at high temperature and high frequency and investigate the effect of the shape and electrical parameters of the FDC layer on electric field reduction.…”

Section: Introductionmentioning

confidence: 99%

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Tailoring Electric Field Distortion in High-Voltage Power Modules Utilizing Epoxy Resin/Silicon Carbide Whisker Composites with Field-Dependent Conductivity

Wang

Chen

Huang

et al. 2022

ACS Appl. Electron. Mater.

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This paper reports the performance of an epoxy resin/silicon carbide whisker (EP/SiCw) composite (1–5 wt %) as the field-dependent conductivity (FDC) layer for electric field reduction in the high-voltage power module. The experiments consist of a field emission scanning electron microscope (FESEM), thermal conductivity, Fourier transform infrared (FT-IR) spectroscopy, thermally stimulated discharge current (TSDC), space charge, DC conductivity, and dielectric spectroscopy. The DC conductivity and dielectric spectroscopy are used for DC and AC stationary electric field simulations, respectively. The electric field reduction of EP/SiCw composites in the power module is analyzed, and the void defect in the FDC layer is also identified. The observed percolation threshold of the EP/SiCw composites is 3 wt %, and the DC electric field near the triple point decreases significantly by 74.8% under 10 kV when a 5 wt % EP/SiCw composite is applied for the FDC layer. It was found that the efficient threshold operating frequency of the FDC layer is around 10 kHz. The FDC layer can significantly reduce the electric field under AC voltage below 10 kHz. Although the power loss with the FDC layer increases obviously without the FDC layer, it is still lower than 1 W at 1 MHz, which is negligible for industrial applications. Notably, the void in the FDC layer is identified by the slowly increased dielectric loss with the increase of frequency through dielectric spectroscopy simulation.

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Section: Experimental Results and Analysismentioning

confidence: 99%

Section: Experimental Results and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Tailoring Electric Field Distortion in High-Voltage Power Modules Utilizing Epoxy Resin/Silicon Carbide Whisker Composites with Field-Dependent Conductivity

Wang

Chen

Huang

et al. 2022

ACS Appl. Electron. Mater.

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show abstract

“…The increase can be explained by the potential-energy well model of ionic conduction, which states that the number and velocity of ionic charges increase with the electric field strength [19]. At high electric field strengths, electrons contribute to the conduction by generation (Poole-Frenkel and Fowler-Nordheim mechanisms) and their stepwise drift in the electric field (hopping mechanism) [14,20]. For polymers, additional changes of the electrical properties occur around the glass transition temperature T g [13,17].…”

Section: Conductivitymentioning

confidence: 99%

Implications of Nonlinear Material Parameters on the Dielectric Loss under Harmonic Distorted Voltages

et al. 2021

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The increasing number of power electronic devices in electrical grids may lead to harmonic distorted voltages, which are considered to be possible causes of component failures. In this study, the dielectric losses of epoxy polymer and functionally filled silicone rubber (f-SiR) samples are investigated under harmonic distorted voltages in terms of their dielectric losses and the consequent heat source density within the material. The results suggest that the epoxy polymer samples behave linearly to the electric field strength and therefore allow good predictability of the dielectric losses. The investigated f-SiR samples exhibit a nonlinear behaviour when an electric field threshold is exceeded. The subsequent direct loss measurements under harmonic distorted voltage reveal a sharp rise of the dielectric loss with increasing electrical field strength. This leads to a higher risk of excessive heat in the material when harmonics are present. In conclusion, the investigation highlights the difficulties of estimating dielectric losses in nonlinear dielectric materials when distorted voltages are present.

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Investigation of charge dynamics in the corona‐aged silicone rubber alumina nanocomposite

et al. 2023

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The effect of corona aging on the surface potential dynamics and charge trap characteristics of silicone rubber alumina nanocomposite are examined using surface potential decay measurement. The aging was carried out by exposing the specimens to corona stress generated by a high‐frequency AC multi needle‐plane electrode system. The results show that the addition of alumina filler increases the surface potential decay time and maximum trap energy. A reduction in trap depth is observed with the corona aging, and the addition of alumina filler limits the degradation and change in charge trap distribution. The results of an analysis of the space charge behavior of different nanocomposites and their comparison are presented. The space charge variation analysis was carried out under the applied electric field of 20 kV/mm at room temperature using the pulsed electro‐acoustic technique (PEA). Based on the results, the charge density, electric field, and charge trap distribution were deduced. It is concluded that the space charge concentration and enhancement in the electric field of the aged material increases with aging duration and it is maximum in the case of 60 min corona‐aged pure silicone rubber. Analysis of the recovery of the charge dynamics of the sample after corona discharges at the different time intervals shows that the recovery of trap distribution is faster for a virgin sample and slower for the sample with 5 wt% of alumina.

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Nonlinear conduction and surface potential decay of epoxy/SiC nanocomposites

Cited by 40 publications

References 35 publications

Tailoring Electric Field Distortion in High-Voltage Power Modules Utilizing Epoxy Resin/Silicon Carbide Whisker Composites with Field-Dependent Conductivity

Tailoring Electric Field Distortion in High-Voltage Power Modules Utilizing Epoxy Resin/Silicon Carbide Whisker Composites with Field-Dependent Conductivity

Implications of Nonlinear Material Parameters on the Dielectric Loss under Harmonic Distorted Voltages

Investigation of charge dynamics in the corona‐aged silicone rubber alumina nanocomposite

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