scholarly journals Electrical Treeing and Partial Discharge Characteristics of Epoxy/Silica Nanocomposite under Alternating Current

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jae-Jun Park
Keyword(s):  
Epoxy Matrix ◽  
Partial Discharge ◽  
Hydrophobic Surface ◽  
Electrical Equipment ◽  
Alternating Current ◽  
Neat Epoxy ◽  
Epoxy System ◽  
Breakdown Time ◽  
Base Resin ◽  
Nanosilica Particles

The hydrophilic surface of fumed nanosilica was modified to a hydrophobic surface by treating it with a trimethyl silane coupling agent, and epoxy nanocomposites were prepared by mixing the modified nanosilica (0 phr, 1 phr, 3 phr, 5 phr, and 7 phr) in an epoxy matrix, where the unit phr means the parts per one hundred grams of epoxy base resin. To apply the nanocomposites to heavy electrical equipment, the effects of the modified nanosilica on the long-term treeing phenomena and the partial discharge (PD) resistance were studied under high voltage alternating current (HVAC) conditions. The bonding of trimethyl silane on the nanosilica surface was confirmed by the appearance of new peaks for the CH2 and CH3 groups in Fourier-transform infrared spectroscopy analysis. To observe the even dispersion of the modified nanosilica particles in the epoxy matrix, a transmission electron microscope was employed, and it was found that 1 phr of the modified nanosilica was uniformly dispersed; however, as the nanosilica content was increased, its aggregation became somewhat severe. The longest HVAC treeing breakdown time was found in an epoxy nanocomposite with 1 phr of alkyl-modified nanosilica, and the time was 17,412 min, which was 143.9 times longer than the 121 min required for a neat epoxy system. In a nanocomposite with 5 phr of modified nanosilica, PD resistance was found to be 12.5 times higher than that of the neat epoxy system.

Exceptionally high thermal and electrical conductivity of three-dimensional graphene-foam-based polymer composites

RSC Advances ◽  
2016 ◽  
Vol 6 (27) ◽  
pp. 22364-22369 ◽  
Author(s):  
Zhiduo Liu ◽  
Dianyu Shen ◽  
Jinhong Yu ◽  
Wen Dai ◽  
Chaoyang Li ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Polymer Composites ◽  
Epoxy Matrix ◽  
Three Dimensional ◽  
Neat Epoxy ◽  
Graphene Foam

Three dimensional graphene foam incorporated into epoxy matrix greatly enhance its thermal conductivity (up to 1.52 W mK−1) at low graphene foam loading (5.0 wt%), over an eight-fold enhancement in comparison with that of neat epoxy.

Testing of Underground Power Cables

2016 ◽  
pp. 288-317
Keyword(s):  
Power Systems ◽  
Electrical Power ◽  
Current Source ◽  
Electrical Equipment ◽  
Alternating Current ◽  
Power Cables ◽  
Test Procedures ◽  
Electrical Power Systems ◽  
Insulation Systems ◽  
Underground Power Cables

Probably 80% of all testing performed in electrical power systems is related to the verification of insulation quality. This chapter briefly describes the fundamental concepts of insulation testing including – insulation behavior, types of tests, and some test procedures. Most electrical equipment in utility, industrial, and commercial power systems uses either 50 or 60 Hz alternating current. Because of this, the use of an alternating current source to test insulation would appear to be the logical choice. However, as will be described a little later, insulation systems are extremely capacitive. For this and other reasons, DC has found a large niche in the technology. Before we can really evaluate the value of one system as opposed to the other (e.g. AC vs DC), let us examine how each type of voltage affects insulation. Testing of underground power cables are reported by NS161. (2014). IEC 6038. (1979). IEC Standard 60228. (1979). IEC60229. (2007). IEC60230. (1974). IEC60233. (1981). IEC 60332 (1974). IEC 6071 (2008). IEC 60270. (2000), IEC 60287. (2002).

scholarly journals Evaluation on Partial Discharge Intensity of Electrical Equipment Based on Improved ANFIS and Ultraviolet Pulse Detection Technology

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 126561-126570 ◽  
Author(s):  
Jingang Wang ◽  
Peiyuan Li ◽  
Xudong Deng ◽  
Na Li ◽  
Xi Xie ◽  
...  
Keyword(s):  
Partial Discharge ◽  
Electrical Equipment ◽  
Pulse Detection ◽  
Detection Technology

Study on Monitoring System for Partial Discharge of Electrical Equipment

2014 ◽  
Vol 12 (2) ◽  
Author(s):  
Miaofen Zhu ◽  
Guojin Chen ◽  
Ming Xu ◽  
Tingting Liu ◽  
Dong Xie ◽  
...  
Keyword(s):  
Monitoring System ◽  
Partial Discharge ◽  
Electrical Equipment

Study on Discharge of Separated Water Droplets in DC Field

2011 ◽  
Vol 130-134 ◽  
pp. 3276-3279
Author(s):  
Zong Xi Zhang ◽  
Shan Feng Yin
Keyword(s):  
Electric Field ◽  
Hydrophobic Surface ◽  
Electrical Equipment ◽  
Water Droplets ◽  
Surface Flashover ◽  
Voltage Drops ◽  
Flashover Voltage ◽  
Dc Electric Field ◽  
Water Drops ◽  
And Migration

With the accelerating construction of strong smart grid, and the grid voltage level rising, performance requirements for the electrical insulation of electrical equipment also continue to increase. In terms of the advantages of RTV on antifouling, RTV-based paints coated insulator coating capacity of its flash tolerance can significantly increase, mainly due to RTV coating hydrophobic hydrophobicity and migration. But when the hydrophobic surface is in the fully wet, many small drops of water in the surface will be gathered into big drops of water, and these large droplets will distort the surface electric field of the medium. So the flashover voltage of the hydrophobic surface’s separated water droplets under DC electric field are analyzed comparatively in this paper, while some influencing factors such as different medias and volume of water drops, are introduced in specific experiments, and their effects on the flashover voltage are analyzed; under DC electric field experiment on the surface of hydrophobic and hydrophilic surface flashover voltage drops separation characteristics were studied.

scholarly journals Improved Performance of an Epoxy Matrix as a Result of Combining Graphene Oxide and Reduced Graphene

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
L. Ramos-Galicia ◽  
L. N. Mendez ◽  
Ana Laura Martínez-Hernández ◽  
A. Espindola-Gonzalez ◽  
I. R. Galindo-Esquivel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graphene Oxide ◽  
Modulus Of Elasticity ◽  
Epoxy Matrix ◽  
Neat Epoxy ◽  
Synergic Effect ◽  
Reduced Graphene ◽  
Improved Performance ◽  
Tensile Toughness

We present an easy and effective way to improve the mechanical properties of an epoxy matrix by reinforcing it with a combination of graphene oxide (GO) and reduced graphene oxide (RGO). These nanocomposites were prepared with different load of nanofillers: 0.1, 0.4, 0.7, 1.0 wt% and a neat epoxy. Ratios of graphene oxide and reduced graphene (GO : RGO) employed were: 0 : 1, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, and 1 : 0. Results show that with only 0.4 wt% and a ratio 0.2 : 0.75 of GO : RGO, tensile strength and tensile toughness are 52% and 152% higher than neat epoxy while modulus of elasticity was improved~20%. The obtained results suggest that it is possible achieve advantageous properties by combining graphene in oxidized and reduced conditions as it shows a synergic effect by the presence of both nanofillers.

Design of Diagnosis System for Insulation Degradation by Using Neurofuzzy Model

2000 ◽  
Vol 4 (5) ◽  
pp. 368-372
Author(s):  
Yigon Kim ◽  
◽  
Yang Hee Jung ◽  
Yong Chul Bae
Keyword(s):  
Numerical Simulation ◽  
Early Warning ◽  
Partial Discharge ◽  
Data Acquisition System ◽  
Electrical Equipment ◽  
New Method ◽  
Insulation Aging ◽  
Insulation Degradation ◽  
On Line ◽  
Data Design

Insulation aging diagnosis provides early warning of electrical equipment defects that helps avoid loss from unexpected production line shutdown. Since relations of insulation aging and partial discharge dynamics are nonlinear, it is very difficult to provide early warning in electrical equipment. This paper suggests a new method for diagnosing insulation aging that measures partial discharge on-line from DAS(Data Acquisition System) and acquires 2D patterns from analyzing it using wavelets. Using this data, design of a neurofuzzy model that diagnoses electrical equipment is investigated. Validity of the new method is confirmed by numerical simulation.

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