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The problem of ensuring the effective functioning of the measuring data acquisition system of RLC-parameters for non-electric objects such as the objects of an environment, food industry, agriculture etc. has been actualized. It has been suggested to conduct remote metrological control at the site of analytical unit's exploitation with the use of differential measurement method and code-controlled...
Water tree generated in insulation parts of the XLPE (Cross Linked Polyethylene) cable is concerned as one of the causes of deterioration or breakdown. For the stable supply of electric power, the facilitated and accurate diagnosis technique is important to measure the deterioration of power cable. In our previous study, we proposed a residual charge measurement method using pulse voltage (charge...
This paper presents the influence of temperature on the DC conductivity the electrical pressboard impregnated with synthetic ester in the measuring temperature range of from 20°C to 80°C and the electric field intensity 10 kV/m. With Arrhenius plots for pressboard sample about the moisture content 0.6% wt. and for the electric field intensity was determined coefficients of determination R2, which...
Insulation failure between the electrical sheets of electrical machines or transformers might occur due to the burrs formed during the cutting process. Together with welding seams or screws used to hold the stack together, the burrs provide a conducting path for eddy currents. In this paper, equivalent conductivities of the EI core with and without interlaminar contacts are determined using 3D finite...
Micro-Macro thinking is students' ability to understand concepts and models at the microscopic (typically unseen) level, and link them to their corresponding manipulable variables at the 'macroscopic' (mostly tangible and measurable) level. For example, in the domain of basic analog electronics, learners are expected to relate the microscopic structure of atoms and scientific models of electron motion...
This paper presents an analysis on image reconstruction for cross sections of the human forearm by means of electrical impedance tomography. The impact of the algorithm and reconstruction parameters are discussed considering a complex geometrical model. The results show that a diffuse reconstruction identifying the main geometry components is possible; however, it is difficult to identify small features...
This research proposes the hot filament chemical vapor deposition (HFCVD) for synthesis of p-type and n-type diamond by doping of boron trioxide (B2O3) and phosphorous pentoxide (P2O5) in ethyl alcohol (C2H5OH), respectively. The synthesis was conducted for 180 h with annealing under hydrogen atmosphere every 60 h to improve the quality of the diamond. Composition of the synthetic diamond was analyzed...
In this paper the slow polarization processes were investigated on 1 mm thick PVC samples. The specimens contained four different mass fraction of di-octyl phthalate (DOP) plasticizer. This polymer type is a widely used cable insulating material in the electrical industry e.g. low voltage distribution cables, cables in nuclear power plants etc. By means of a Megger IDAX 300 device, dissipation factor...
The Hall effect measurement data in the case of switching the conduction by electric field is presented in the paper. It is shown that a sharp decrease of both carrier mobility and density occurs at switch moment. Possible mechanisms of the switch are discussed.
Gas Insulated Substation (GIS) under High Voltage Direct Current (HVDC) are becoming widely investigated with the development of DC networks. Under DC voltage, mechanism of charge accumulation on the insulation surface is of major importance since it may distort the electric field distribution. The latter directly depends on material's conduction and so, on its volume and surface conductivities. Previous...
Imaging objects in electrical impedance tomography (EIT) measurement are often in a dynamic evolution process, and exploiting the spatial-temporal properties for the dynamic reconstruction objects is crucial for the improvement of the reconstruction quality. In this paper, the linearized equation system for dynamic EIT is established based on spatio-temporal representation. Due to the spatial redundancy...
The paper presents the effect in removing organic compounds from water that the Surface gliding discharges (SGD) has it. A SGD is an electrical discharge, formed between two divergent electrodes thin type, “wire type”, generated in a flow of gas, with a high flow rate. The non-thermal plasma, in contact with the solution film formed on the walls of reactor, leads to the organic compound disolved in...
This paper is focused on the description of phenomenon called "floating water bridge" and several experiments in our high voltage laboratory which are joined with this phenomenon. Water bridges bring some new knowledge in chemistry, electrochemistry, lighting technology and high voltage field. In this paper we will be dedicated space for describing the properties of water bridges in the...
We have developed a new method “direct current integrated charge (DCIC) method” for evaluating a deterioration of insulating materials in power equipments. The three important dielectric parameters, that is, conductivity, relative permittivity, and accumulated charge amounts are evaluated simultaneously by a relatively simple treatment of the method. Since the total amount of charges is found as an...
The communication line installed nearby the high-speed train railroad has induced voltage caused by high electric current which is supplied to electric car line. At this point, shielding effect can be expected in communication line, if structure which includes metals is placed around. In this paper, the screening effect was analyzed through experiments when a metallic pipe was buried near the communication...
Faults in high voltage insulator generally occur due to pollution flashover, which is one of the most crucial problem resulted by cumulative effect of both pollution and moisture. In this paper, the effect of contaminants on the performance of flashover voltage of porcelain insulator under various environmental conditions has studied by performing artificial pollution tests that nearly reflects the...
Weakly electric fish use self-established electric field to sense the underwater environment that may be cluttered and turbid. Previous works on building artificial counterparts are limited to simplest cases, as no analytical solutions exist under complex boundary conditions. Universal numerical approaches like Finite Element Method (FEM) and Boundary Element Method (BEM) suffer from lengthy meshing...
The inception of vapor bubbles and discharges in water under high voltage impulses of long duration (500 µs) is investigated experimentally, and by numerical simulation. Time delay to bubble and discharge inception are measured versus conductivity and voltage, using fast visualization and optical detection with a laser light diffusion system. A decrease of gap resistance versus time is first observed,...
The nonwovens and nanofibers as a new material for possible improving properties of electrical insulation are introduced in this paper. Nanofibers were used to modify a commonly used two-component like mica-based high voltage electrical insulating material. The tested material in the form of resin-rich sheets was modified using a various number of layers (1, 2 and 3) of the nanofibers made from Polyamide...
DC electrical insulation is critical for the reliable operation of subsea DC electrical systems. Contamination due to exposure to seawater may significantly affect the reliability of DC insulation. This paper reports the impact of seawater-related contamination on DC-related properties of epoxy insulation. Diffusion coefficients and saturation levels of seawater in the insulation were measured through...
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