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.
Multilayer polyethylene is a material that is generally employed as insulation for the HVDC isolations. In this paper, the influence of the dielectric thickness on space charge dynamic has been studied. For example, low-density polyethylene (LDPE) and Fluorinated Ethylene Propylene (FEP) sandwiched between two electrodes were subjected to high voltage application for the extended duration of time...
Water droplets on the surface of silicon rubber were investigated under the influence of non-uniform electric fields. Several parameters of water droplets were investigated, such as the positioning of the droplets regarding the electrodes. The most striking conclusion is that the flashover voltage and electric field distribution depends on the positioning of the droplets from the electrodes.
This research work presents the distribution of the electric field in point-barrier-plane air gaps taking into account the presence of a space charge under electric stress. A new approach of numerical simulation has been applied to study the barrier effect on the electric field distribution using COMSOL Multiphysics®. The introduction of an insulating barrier leads to a reduction of the electric field...
The High electric field electron transport characteristics in a hexagonal SiC polytype are exposed in this paper. Simulations of the electrons behavior are based on a non-parabolic ensemble Monte Carlo model (EMC). This EMC is implemented to solve the semiclassical Boltzmann equation under high electric field conditions. Also, for more accurate results some effects such as temperature, phonons and...
The electromagnetic field is an interest scientific subject on overhead transmission lines OTL under high voltage for the reason of their risk on the living organisms such as blood leukemia and others. The aim of this paper is to calculate the electric potential, electric field and the magnetic field around and near of high voltage transmission lines using The ComsolMultyphisics program package based...
In order to evaluate the insulation condition of gas insulated switchgear (GIS) by using the ultra-high frequency (UHF) method, attempt to estimate PD current using the finite difference time domain (FDTD) method was carried out. The influence of PD current parameters and the position of measuring point on the received electromagnetic (EM) waves was studied. The EM waves received by using UHF sensors...
In order to replace the SF6 gas with strong greenhouse effect in the high-voltage switchgear, CO2 has become one of the hotspots. In this paper, LW35-40.5(G)/T2500(3150)-31.5 gas-blast circuit-breaker is used as the research object to study the dielectric recovery characteristics of CO2 gas-blast arc chamber under no-load breaking, so that the theoretical basis for the development of CO2 circuit-breaker...
This paper presents the optimization scheme to improve the interruption performance of a gas circuit breaker, which must carry out the interruption duty within specific arcing time for successful operation. The systematic process of design optimization was proposed by using the Bezier curve and sequential approximation technique for satisfying both medium and maximum arcing time. Depending on the...
During the making operations for the back-to-back capacitor banks switching, the inrush current arcs can locally melt the contact surfaces of vacuum interrupters (VIs) in prestrike processes. The condition of the contact surface can significantly influences the behaviors of the inrush current prestrike arcs. The objective of this paper is to determine the influence of contact plate slots on inrush...
A novel TFET known as Double Source Tunnel FET (DS-TFET) is proposed in this paper, which provides higher ON current (ID-ON) with smaller turn-on voltage as compared to present Si based Tunnel FETs. The tunneling area is considerably enhanced which in turn increased the on-current ID-ON (∼29.2 μA/μm) for a smaller turn-on voltage (Vtu = 0.15 volt). The results of rigorous 2D simulation are presented...
In order to meet the trend of miniaturization, large capacity and intelligence of the current vacuum circuit breaker, a new model of three-phase disc rotation vacuum circuit breaker has been proposed, in which the main circuit distribution was changed from the same direction to the opposite. Besides, some adjustments were made to the position of operating mechanism. The electric field distribution...
Insulating liquid, because of high breakdown strength and superior self-recovery property, is widely applied to intense electron beam accelerator, transformer, and superconducting fault current limiters, etc. However, the formation of bubbles caused by heat transfer in power equipment seriously hurts the performance of the insulating strength in liquid. The objective of this paper is to study the...
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...
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...
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.