Space-charge characteristics in polyethylene

Wang, X.; Yoshimura, N.; Murata, Koichi; Tanaka, Yasuhiro; Takada, Tatsuo

doi:10.1063/1.368221

Cited by 29 publications

(23 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Under the electrical stress, the space charge will originate and accumulate within the insulating materials, which may distort the internal electric field distribution and therefore, influence the dielectric breakdown performance [40,41]. A lot of efforts have been made to find the effective ways to decay/suppress the space charge in the insulating materials with an attempt to enhance the dielectric strength and lifetime of insulating materials [42,43].…”

Section: Ferrofluids In Transformersmentioning

confidence: 99%

See 1 more Smart Citation

Study of Dielectric Breakdown Performance of Transformer Oil Based Magnetic Nanofluids

Rafiq

et al. 2017

Energies

View full text Add to dashboard Cite

Abstract:Research on the transformer oil-based nanofluids (NFs) has been raised expeditiously over the past decade. Although, there is discrepancy in the stated results and inadequate understanding of the mechanisms of improvement of dielectric nanofluids, these nanofluids have emerged as a potential substitute of mineral oils as insulating and heat removal fluids for high voltage equipment. The transformer oil (TO) based magnetic fluids (ferrofluids) may be regarded as the posterity insulation fluids as they propose inspiring unique prospectus to improve dielectric breakdown strength, as well as heat transfer efficiency, as compared to pure transformer oils. In this work, transformer oil-based magnetic nanofluids (MNFs) are prepared by dispersal of Fe 3 O 4 nanoparticles (MNPs) into mineral oil as base oil, with various NPs loading from 5 to 80% w/v. The lightning impulse breakdown voltages (BDV) measurement was conducted in accordance with IEC 60897 by using needle to sphere electrodes geometry. The test results showed that dispersion of magnetic NPs may improve the insulation strength of MO. With the increment of NPs concentrations, the positive lightning impulse (LI) breakdown strength of TO is first raised, up to the highest value at 40% loading, and then tends to decrease at higher concentrations. The outcomes of negative LI breakdown showed that BDV of MNFs, with numerous loadings, were inferior to the breakdown strength of pure MO. The 40% concentration of nanoparticles (optimum concentration) was selected, and positive and negative LI breakdown strength was also further studied at different sizes (10 nm, 20 nm, 30 nm and 40 nm) of NPs and different electrode gap distances. Augmentation in the BDV of the ferrofluids (FFs) is primarily because of dielectric and magnetic features of Fe 3 O 4 nanoaprticles, which act as electron scavengers and decrease the rate of free electrons produced in the ionization process. Research challenges and technical difficulties associated with ferrofluids for practical applications are mentioned. The advantages and disadvantages linked with magnetic fluids are also presented.

show abstract

Section: Ferrofluids In Transformersmentioning

confidence: 99%

“…The transformer oil-based ferrofluids possess many performance advantages as compared to transformer oils and are summarized as follows [9][10][11][12][13][21][22][23][24][30][31][32][33][40][41][42][43][44]:…”

Section: Advantages Of Transformer Oil-based Ferrofluidsmentioning

confidence: 99%

Study of Dielectric Breakdown Performance of Transformer Oil Based Magnetic Nanofluids

Rafiq

et al. 2017

Energies

View full text Add to dashboard Cite

show abstract

“…Aging of oil-paper can eventually threaten the safe operation of electrical devices. The space charge will accumulate within the paper materials under the action of DC high voltage, leading to the distortion of internal local electrical field distribution [3,4]. Therefore, the aging speed of paper material is accelerated.…”

Section: Introductionmentioning

confidence: 99%

Space Charge Behavior in Paper Insulation Induced by Copper Sulfide in High-Voltage Direct Current Power Transformers

Liao

Yang

et al. 2015

Energies

View full text Add to dashboard Cite

Abstract:The main insulation system in high-voltage direct current (HVDC) transformer consists of oil-paper insulation. The formation of space charge in insulation paper is crucial for the dielectric strength. Unfortunately, space charge behavior changes because of the corrosive sulfur substance in oil. This paper presents the space charge behavior in insulation paper induced by copper sulfide generated by corrosive sulfur in insulation oil. Thermal aging tests of paper-wrapped copper strip called the pigtail model were conducted at 130 °C in laboratory. Scanning electron microscopy (SEM) was used to observe the surface of copper and paper. Pulse electroacoustic (PEA) and thermally stimulated current (TSC) methods were used to obtain the space charge behavior in paper. Results showed that both maximum and total amount of space charge increased for the insulation paper contaminated by semi-conductor chemical substance copper sulfide. The space charge decay rate of contaminated paper was significantly enhanced after the polarization voltage was removed. The TSC results revealed that copper sulfide increased the trap density and lowered the shallow trap energy levels. These results contributed to charge transportation by de-trapping and trapping processes. This improved charge transportation could be the main reason for the decreased breakdown voltage of paper insulation material. OPEN ACCESSEnergies 2015, 8 8111

show abstract

“…Also the branch length and molecular weight of the three PE types have a large influence on the space charge formation. 76 Furthermore, when introducing nucleating agent (which could be sorbitol based, HDPE, or metal-locene catalyzed PE) to LDPE, [77][78][79] more but smaller and less perfect spherulites appear, with more interfaces between crystalline and amorphous phases. This results in a higher and more homogeneously distributed conductivity, and thus less space charge.…”

Section: Microstructurementioning

confidence: 99%

Research progress on space charge characteristics in polymeric insulation

Zhang¹,

Christen

Meng³

et al. 2016

J. Adv. Dielect.

View full text Add to dashboard Cite

Due to their excellent electrical insulation properties and processability, polymer materials are used in many electrical products. It is widely believed that space charge plays an important role for the electric field distribution, conduction, ageing, and electric breakdown of polymeric insulation. This paper reviews measurements and characteristics of space charge behavior which mainly determined by the pulsed electro-acoustic (PEA) measurement technique. Particular interests are the effects of the applied voltage, the electrodes, temperature, humidity, microstructure, additives, and filler materials on accumulation, distribution, transport, and the decay of space charge in polymeric materials. This review paper is to provide an overview on various space charge effects under different conditions, and also to summarize the information for polymeric materials with suppressed space charge and improved electrical behavior.

show abstract

Space-charge characteristics in polyethylene

Cited by 29 publications

References 20 publications

Study of Dielectric Breakdown Performance of Transformer Oil Based Magnetic Nanofluids

Study of Dielectric Breakdown Performance of Transformer Oil Based Magnetic Nanofluids

Space Charge Behavior in Paper Insulation Induced by Copper Sulfide in High-Voltage Direct Current Power Transformers

Research progress on space charge characteristics in polymeric insulation

Contact Info

Product

Resources

About