scholarly journals Experimental Study on the Dielectric Breakdown Voltage of the Insulating Oil Mixed with Magnetic Nanoparticles

2012 ◽  
Vol 32 ◽  
pp. 327-334 ◽  
Author(s):  
Jong-Chul Lee ◽  
Woo-Young Kim
Keyword(s):  
Experimental Study ◽  
Magnetic Nanoparticles ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Insulating Oil

Experimental Study of the Compatibility of Insulating Oil in Transformers

2015 ◽  
Vol 19 (sup8) ◽  
pp. S8-680-S8-684 ◽  
Author(s):  
Y.-H. Qian ◽  
W. Su ◽  
Y.-B. Huang ◽  
Z.-S. Zhong
Keyword(s):  
Experimental Study ◽  
Insulating Oil

scholarly journals Magnetoviscosity of a Magnetic Fluid Based on Barium Hexaferrite Nanoplates

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1870
Author(s):  
Dmitry Borin ◽  
Robert Müller ◽  
Stefan Odenbach
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Magnetic Nanoparticles ◽  
External Magnetic Field ◽  
Shear Flow ◽  
Magnetic Fluid ◽  
Barium Hexaferrite ◽  
Dipole Interaction ◽  
Field Dependent ◽  
Fluid Behaviour

This paper presents the results of an experimental study of the influence of an external magnetic field on the shear flow behaviour of a magnetic fluid based on barium hexaferrite nanoplates. With the use of rheometry, the magnetoviscosity and field-dependent yield-stress in the fluid are evaluated. The observed fluid behaviour is compared to that of ferrofluids with magnetic nanoparticles having high dipole interaction. The results obtained supplement the so-far poorly studied topic of the influence of magnetic nanoparticles’ shape on magnetoviscous effects. It is concluded that the parameter determining the observed magnetoviscous effects in the fluid under study is the ratio V2/l3, where V is the volume of the nanoparticle and l is the size of the nanoparticle in the direction corresponding to its orientation in the externally applied magnetic field.

Performance Investigation of a Four Stroke Diesel Engine, Using Water-Based Ferrofluid as an Additive

2011 ◽  
Author(s):  
F. Daneshvar ◽  
N. Jahani ◽  
M. B. Shafii
Keyword(s):  
Experimental Study ◽  
Magnetic Nanoparticles ◽  
Diesel Engine ◽  
Diesel Fuel ◽  
Engine Performance ◽  
Brake Specific Fuel Consumption ◽  
Engine Exhaust ◽  
Brake Thermal Efficiency ◽  
Diesel Fuels ◽  
Water Based

In this experimental study, a four stroke diesel engine was conducted to investigate the effect of adding water-based ferrofluid to diesel fuel on engine performance. To our knowledge, Magnetic nanoparticles had not been used before. To this end, emulsified diesel fuels of 0, 0.4, and 0.8 water-based ferrofluid/Diesel ratios by volume were used as fuel. The ferrofluid used in this study was a handmade water-based ferrofluid prepared by the authors. The results show that adding water-based ferrofluid to diesel fuel has a perceptible effect on engine performance, increasing the brake thermal efficiency relatively up to 12%, and decreasing the brake specific fuel consumption relatively up to 11% as compared to diesel fuel. In addition, the results indicate that increasing ferrofluid concentration will magnify the results. Furthermore, it was found that magnetic nanoparticles can be collected at the engine exhaust using magnetic bar.

A Study of Oxide Etch Angle of Edge Termination Field Plate for Fabrication of SiC SBD

2017 ◽  
Vol 730 ◽  
pp. 102-105
Author(s):  
Ey Goo Kang
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Power Semiconductor ◽  
Field Plate ◽  
Edge Termination ◽  
Power Semiconductor Devices ◽  
Silicon Materials ◽  
Generation Power

The silicon carbide (SiC) material is being spotlighted as a next-generation power semiconductor material due to the characteristic limitations of the existing silicon materials. SiC has a wider band gap, higher breakdown voltage, higher thermal conductivity, and higher saturation electron mobility than Si. However, actual SiC SBDs exhibit a lower dielectric breakdown voltage than the theoretical breakdown voltage that causes the electric field concentration, a phenomenon that occurs on the edge of the contact surface as in the conventional power semiconductor devices. In this paper, we designed an edge termination structure using a field plate structure through oxide etch angle control, and optimized the structure to obtain a high breakdown voltage. The experiment results indicated that oxide etch angle was 45° when the breakdown voltage characteristics of the SiC SBD were optimized and a breakdown voltage of 681V was obtained.

scholarly journals Streamer evolution arrest governed amplified AC breakdown strength of graphene and CNT colloids

2019 ◽  
Vol 85 (3) ◽  
pp. 30402 ◽  
Author(s):  
Purbarun Dhar ◽  
Ankur Chattopadhyay ◽  
Lakshmi Sirisha Maganti ◽  
Anilakkad Raman Harikrishnan
Keyword(s):  
Mathematical Model ◽  
Carbon Nanotubes ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Effective Electron ◽  
Dielectric Breakdown Strength ◽  
Mineral Oils ◽  
Two Parameter ◽  
Fundamental Mechanism

The present paper explores the concept of improving the AC dielectric breakdown strength of insulating mineral oils by the addition of graphene or carbon nanotubes (CNTs) to form stable dispersions. Experimental observations of graphene and CNT nano-oils show that not only improved average breakdown voltage, but also significantly improved reliability and survival probabilities of the oils under AC high voltage stressing is achieved. Improvement of the tune of ∼70–80% in the AC breakdown voltage of the oils has been obtained. The study examines the reliability of such nano-colloids using a two-parameter Weibull distribution and the oils show greatly augmented electric field bearing capacity. The fundamental mechanism responsible for such observed outcomes is reasoned to be delayed streamer development and reduced streamer growth rates due to effective electron scavenging. A mathematical model based on the principles of electron scavenging is proposed to quantify the amount of electrons scavenged by the nanostructures.

scholarly journals Fabrication of Fe3O4@SiO2 Nanofluids with High Breakdown Voltage and Low Dielectric Loss

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 716
Author(s):  
Bin Du ◽  
Yu Shi ◽  
Qian Liu
Keyword(s):  
Dielectric Loss ◽  
Breakdown Voltage ◽  
Shell Thickness ◽  
Electrical Breakdown ◽  
Sio2 Nanoparticles ◽  
Electrical Equipment ◽  
Insulating Oil ◽  
Low Dielectric ◽  
Sio2 Shell ◽  
High Dielectric

Insulating oil modified by nanoparticle (often called nanofluids) has recently drawn considerable attention, especially concerning the improvement of electrical breakdown and thermal conductivity of the nanofluids. However, traditional insulating nanofluid often tends to high dielectric loss, which accelerates the ageing of nanofluids and limits its application in electrical equipment. In this paper, three core-shell Fe3O4@SiO2 nanoparticles with different SiO2 shell thickness were prepared and subsequently dispersed into insulating oil to achieve nanofluids. The dispersion stability, breakdown voltages and dielectric properties of these nanofluids were comparatively investigated. Experimental results show the alternating current (AC) and positive lightning breakdown voltage of nanofluids increased by 30.5% and 61%, respectively. Moreover, the SiO2 shell thickness of Fe3O4@SiO2 nanoparticle had significant effects on the dielectric loss of nanofluids.

Polarity Effect and Dielectric Breakdown of Composite Ferroelectric Films as the Dielectric for Electrowetting Systems

2018 ◽  
Vol 281 ◽  
pp. 598-603 ◽  
Author(s):  
Wei Qiang Wang ◽  
Yan Su
Keyword(s):  
Thin Film ◽  
Electrical Properties ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Ferroelectric Thin Film ◽  
Ferroelectric Film ◽  
Ferroelectric Films ◽  
Dc Voltage ◽  
Voltage Polarity ◽  
Voltage Frequency

In this paper, we study the electrical properties and breakdown phenomena of BaTiO3/Teflon composite ferroelectric thin film in electrowetting systems. The experimental results showed that the electrowetting effect and the breakdown voltage depend on DC voltage polarity, and this polarity dependence is closely related to the thickness of the ferroelectric film. Under AC voltages, the breakdown voltage increased directly with voltage frequency. These results are useful for designing reliable EWOD devices with low operation voltages and high robustness.

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