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In this paper, Underground distribution power cable of 20,000 lines was diagnosed using VLF(Very Low Frequency) tanô method. The accumulated big data is analyzed statistically with the Weibull distribution, and the 3D model is implemented through the matrix of statistical factors of TD (average of 8 point tanô), DEV(deviation), STDEV (standard deviation) and SKIRT(deviation slope of 8 point tanô)...
Electrical energy networks' reliability is driven by both, the quality and the reliability of its electrical equipment, e.g. power transformers. Local failures inside their oil/paper insulation can cause breakdowns and resulting high outage and penalty costs. Power transformers are tested on partial discharge (PD) activity at a factory routine test. Complementary, UHF PD monitoring can be used to...
This study deals with the polarization and depolarization currents of linear/nonlinear double-layered composites, and sets out to explore interface polarization and depolarization characteristics. The linear layer is pure low density polyethylene (LDPE) matrix. The nonlinear barrier layer is prepared by adding nanofillers (ZnO and SiC) to LDPE with different concentrations. Experimental results show...
Smart grid distribution network consist of power supply cables and two-way communication between the customer and grid which is carried out by Optical Fiber Composite Low-Voltage Cable (OPLC). The concept of OPLC is to merge the power distribution and communication access network together so that one cable can connect the customers to the smart grid through a smart meter, to create an interactive...
Hexagonal boron nitride (h-BN) is an ideal twodimensional dielectric material, with excellent physical, chemical, thermal, mechanical and dielectric properties, which makes it especially attractive for logic device applications. For the h-BN film used as a dielectric layer in graphene-based electronic devices, the insulation performance evaluation under ultra-high DC electric stress is a key issue...
Polymeric outdoor insulation material provides the properties of hydrophobicity, which has an important effect on the functionality in the application. The retention of the hydrophobicity depends on various factors, whereby the combined electric and electrolytic stress is close to the application. In this paper, all of the investigations are focused on silicones. The retention and the recovery of...
A gel is used as the encapsulant of a power device. But there are a lot of uncertain points about the electrical properties of the gel. We have investigated the time series measurement of electric field distributions in propylene carbonate that was a dielectric liquid with large Kerr constant. The propylene carbonate dissolves polymethyl methacrylate resin and becomes gelatinous. It was considered...
Measuring PDIV with 50 Hz sinusoidal waveforms to find what happens using wide bandgap devices having slew rates of x 100 V/ns can give misleading results. Since PDIV tests using wide bandgap devices offers contradicting results, a probabilistic model is proposed to figure the probability density function of PDIV results. This is an intermediate step developing a statistical procedure enabling a more...
Liquid nitrogen impregnated PPLP and Kraft lapped papers are compared in terms of space charge distribution measurements for high voltage insulation in high power HVDC superconducting cables. Measurements with the pressure-wave-propagation method have shown that PPLP and Kraft paper samples behave similarly up to 30 kV/mm. No space charge has been observed in the insulation. Partial discharges at...
Presently, the Partial Discharge (PD) process at DC voltage is not as well known as for AC voltage. In this paper, the characterization of PD activity under DC voltage is studied in order to be used as a future tool for the diagnostic of insulators. The PD is associated with a bipolar charge deployment inside the cavity of the insulating material. PD characterization was usually investigated based...
One of the critical challenges of our times is the rapidly (and constantly) rising demand for electric power and miniaturization of electronic devices. This demand can only be achieved through an increase of the electrical stress acting on dielectrics in electronic and electrical components. Knowledge of their electronic properties is a key to understand ageing and breakdown which are the limiting...
In order to investigate the electrical characteristics and the morphologic development of secondary arc in atmospheric air, a simulative experimental platform of secondary arc for UHV transmission lines was built and the corresponding experimental procedure was introduced in this paper. The discharge waveforms were categorized into three stages: the short-circuit arc period, the transition period...
As the core component of the spacecraft power supply system, the safety and stability of Printed Circuit Boards (PCB) are very important for the whole spacecraft operation. However, PCB faces more insulation problems under abnormal operating conditions. On the one hand, miniaturization and high-density electrical devices result in continually decreasing insulation distance between PCB interconnection...
Gas insulated switchgear (GIS) is a compact metal encapsulated switchgear consisting of high-voltage components such as circuit-breakers and disconnectors, which can be safely set up in confined spaces. However, some GISs have been used for more than 40 years, so characteristic of sealing rubber is considered to be degraded. We find possibility of aging of the sealing rubber by comparing surface characteristics...
In this paper, the zirconia toughened alumina (ZTA) ceramics with different content of zirconia were fabricated. The dielectric relaxation properties were investigated by using thermally stimulated depolarization current (TSDC) method. The observed TSDC peaks were attributed to defect dipole polarization, and the related activation energies were evaluated by a fitting method. The influence of zirconia...
One of the challenges in the microelectronic field is to improve the component reliability. In this work dielectric charging process in capacitive structures under bias voltage is particularly investigated. A new dielectric charging model to study charge accumulation in insulator thin films is presented. It allows a better understanding of charge transport mechanisms and physical charging process...
We propose in this work to use the dielectrophoretic forces to estimate the dielectric permittivity of ceramic powders dispersed in a liquid media. When a divergent electric field is applied to the suspension, the dielectrophoretic force will either repel the particles (negative dielectrophoresis, n-DEP) or attract them (positive dielectrophoresis, p-DEP) to the strong electric field gradient. We...
In a space charge measurement, a threedimensional (3D) measurement technique has been developed by using the PEA method. As a result, space charge distribution and electric field distribution of insulating polymer can be measured even under non-uniform electric field. On the other hand, a current distribution measurement in an insulating polymer cross section has not been realized yet. We have assembled...
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