The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The Partial Discharge Inception Voltage (PDIV) and PD characteristic of mineral oil were described and compared with palm oil. The test was performed by needle-plane electrode configurations. Both mineral- and palm oil were investigated under AC voltage. A comparison study between PDIV and PD activities of the mineral oil Hyrax and palm oil were investigated with the total volume of the oil in the...
In this paper, we successfully demonstrated a software application on the android platform of mobile phone which allows users to have a quick insight of radiated emission generated based on the image of a printed circuit board (PCB) by using analytical method and image processing. For benchmarking the application, a study on the radiated emission of PCBs with the use of electromagnetic compatibility...
Industrial tests of high voltage equipment insulation at impulse voltages are carried out following rigorously described procedures and require, as a rule, long time duration and, implicitly, significant costs. Reducing the duration of these tests, as well as the possibility of disruptive voltage prediction has been always an objective of interest. This paper involved the rigorous statistical processing...
The authors conducted a theoretical and pilot research of the physical phenomenon of a charging decompensation in the course of explosive formation and plasma warming up. This physical phenomenon cannot be described within relativistic electrodynamics. Its existence is predicted by hyper continual electrodynamics. It relies on the hyper continual ideas of space and time within which transition between...
Irreversible electroporation (IRE) uses high-intensity electric pulses of ∼ 100 μs duration to induce cell death through permanent membrane destruction. In this study, monopolar pulses are replaced by bipolar high repeated frequency pulses (BHRFPs) while maintaining a constant total energized time (100 μs), burst number (90), and inter-burst delay (1 s). To observe the damage to the cell membrane...
We utilized a Monte Carlo optimization algorithm on an array of metallic nanoslits of uniform width to maximize the normalized electric field at a focal point. The results indicate optimal hyperspectral focusing of light in the far-field.
Wounds are a major public health issue worldwide and have become a great challenge for the health care system. Pharmacologic methods are costly and not effective. Two promising physical techniques are used to accelerate wound healing: the mechanical vacuum-assisted closure (VAC) therapy and the more affordable and safer electromagnetic field therapies, including pulsed electromagnetic fields (PEMF),...
SCF N2 may have good dielectric properties, so that it has drawn great attention from the scientists worldwide. In this paper, the rod-plate electrode model of 5mm gap with DC voltage was established, and the breakdown process of the SCF N2 was studied under the SC condition with the fluid dynamics method according to the gas-dielectric discharge principle. The results show that the breakdown voltage...
The results presented in this paper relate to the methods of monitoring and establishing the type of the breakdown mechanism basis of the dependence on the static breakdown voltage in the function of the product of the gas pressure and the gap distance in air-filled tube. On that occasion, during the experimental conditions the air pressure was kept constant at 6.65 mbar, while the values of the inter-electrode...
Corona discharge due to a conductive particle in highvoltage system is analyzed using a coupled equation, which consists of Poisson's equation for electric field distribution and a discharge equation for space charge density variation. The charge of a conductive particle is calculated using the finite element method, and the electric force acing on the particle is obtained using the calculated result...
The insulation characteristics of solid materials in high voltage switches directly affect the service life of these switches, which is of great significance to the reliability of power system. The electrical aging lifetime of epoxy resin materials in solid insulation switches is studied in this paper. The electrical aging lifetime test is carried on the epoxy resin materials at room temperature with...
High voltage SF6 circuit breaker must meet the breaking requirement for large short-circuit current, and ensure absence of breakdown after breaking small current. A 126kV high voltage SF6 circuit breaker was used as the research object in this paper. Based on the calculation results of non-equilibrium arc plasma material parameters, the distribution of pressure, temperature and density were calculated...
In this work, we theoretically investigate the L3 cavity with three missing holes in the center. The Photonic cavities have an ultra-low index contrast and are fabricated by SiO2/ZrO2 or SiO2/TiO2 in which the refractive index varies in the range of 1.51 to 1.58 at λ =1.55 μm. We show that cavity modes can be differently tuned depending on the size and the position of the first hole adjacent to the...
The objective in this paper is the introduction of a new method in the design of high voltage insulators by exploiting a meta-heuristic optimization. Indeed, a neural network is used for the prediction of the value of the tangential electric field at the high voltage pin (the area where the value of the electric field is maximum), which will then serve as an objective function to be minimized by the...
The objective of this paper is to determine the dependence of field enhancement factor β on power frequency (50 Hz) voltage in vacuum. A rod-plane vacuum gap was designed in a vacuum interrupter. Shots of ac power frequency voltage were applied at three vacuum gaps till breakdown occurred and the three vacuum gaps were 1.0 mm, 0.8 mm and 0.5 mm, respectively. The field emission current and applied...
When SF6 was designated as a green house gas to be reduced, there has been a wish to use an alternative insulating gas to replace pure SF6 gas. And a fluoroketon, C5F10O attracts great attention as a potential substitute. In this paper, the breakdown characteristics of C5F10O/CO2 as mixtures in nonuniform electric filed and the variation of the mixing ratio with elevation were studied. The positive...
SF6 has been widely used in electrical industry because of its excellent electrical capabilities. However, due to its extremely high Global Warming Potential (GWP), researchers have done lots of investigations on SF6 alternative gases during the last few decades. Unfortunately, all the substitutions have their own drawbacks and limitations and can't be applied in practice. In this paper, the critical...
CF3I has been recognized as an attractive insulating medium for substituting SF6 gas in high-voltage switchgear insulations, because it has low global warming potential (GWP) and an insulation capability that is 1.2 times greater than that of SF6. In this paper, the AC breakdown tests on CF3I/N2 gas mixture have been completed in a sphere-plate geometry. We reveal the effect laws of mixture content,...
The application of vacuum interrupters and vacuum circuit breakers for higher voltage level is strongly expected. In electrical insulation in vacuum, surface flashover on solid insulator is one of the main problems for the higher voltage vacuum interrupters. In this paper, through the review of our recent researches, we discuss on the initiation and development mechanisms of flashover in the configuration...
This paper reports simulation of punch-through gallium nitride (GaN) insulated gate bipolar transistors (IGBTs) with different drift layer thicknesses of t=12 μm and t=17 μm delivering breakdown voltages of VBD=600V and VBD=700V, respectively. The simulated devices are enhancement-mode with the threshold voltage of +3.5V. The leakage current in proposed devices are in the range of 10−9 A/μm. Using...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.