The electromagnetic environment of insulators in substations is more complicated than that transmission lines, this difference gets prominent as the system voltage increases. Considering all influencing factors, paper presents calculation results potential and electric field distribution ceramic insulator strings 1000 kV ultra-high (UHV) substations, using a three-dimensional (3-D) finiteelement method (FEM) software. Factors affect such grading ring, jumper, string structure, mounting...

Graphene has attracted much attention due to its advanced properties. In previous work, the relationship between temperature and conductivity of epoxy-based nanocomposite filled with graphene oxide been experimentally studied. To understand charge transport behaviour, space characteristics at different temperatures field strengths are measured an improved pulsed electroacoustic measurement system, which is designed for high-temperature measurement. From results, epoxy resin (ER) multi-layer...

The transient electric field distribution under lightning impulse voltage (LIV) is vital to the reliability of 750 kV composite cross-arm. However, electrical equipment has usually been substituted by equivalent sinusoidal voltage, without considering variation permittivity with frequency. Using frequency decomposition computation method (FDCM) based on finite element (FEM), this paper presents study LIV for a waveform decomposed via Fourier transformation. complex dielectric functions...

Ultra high voltage (UHV) converter transformer valve-side bushings are the key equipment indirect current (DC) transmission projects, and subjected to large with number of harmonics simultaneously. The electric field distribution is time-dependent under DC voltage, polarity reversal actual waveforms, temperature coupling each other in operation. dynamic characteristics surface charges China's first ± 1100 kV epoxy/paper – SF6 composite insulation trans former bushing 2 h withstand test were...

In this work, mono-layer and multi-layer graphene oxide were used as fillers to be mixed with epoxy resin, where water solution, ultrasonication magnetic stirring achieve an optimal dispersion. The dispersion state of was observed by both scanning electron microscope (short SEM) transmission TEM). Different relaxation processes studied over a wide range temperature frequency impendence analyzer. nonlinear relationship between the electrical conductivity applied electric field strength...

In the present work, we studied dust deposition characteristics on suspended insulators under simulated sandstorm conditions in a laboratory. Based simulation experiments, basic and distribution were studied, such as difference of among sheds at different locations, between large small sheds, relationship quantity flow speed air well experimental duration. Our study provides important insights for more advanced studies this topic future.

This paper presents the design and calibration method of an improved pulsed electroacoustic (PEA) system for space charge measurements, including a novel nanosecond pulse generator electrode system, which can be used under various temperatures arbitrary waveform voltages. The measurement principle PEA is first analyzed, applied voltage proposed to solve problem distortion caused by voltages with different frequency components. For generator, main parameters output pulses are amplitude ∼700...

Abstract Effects of vibration frequency and amplitude on air gap discharge characteristics were studied by simulation experiments through a special model. The results show that in clean environment the are mainly affected minimum distance, while sand/dust–air swing as well distance. Copyright © 2010 Institute Electrical Engineers Japan. Published John Wiley & Sons, Inc.

This paper deals mainly with the effect of water absorption on dielectric properties EPDM/Al(OH)/sub 3/ composites. The relationship between and is investigated by accelerated aging. diffusion coefficient in composites computed, mechanism discussed. results show that permittivity loss tangent closely related content filler particle size. filler-polymer filler-filler interfaces are main path entering composite, which play an important role properties.

Compared with the electrical measurement of discharge, acoustic discharge has advantages in noise reduction and location partial sites. In this paper, a sensitive emission (AE) sensor is used to pick up ultrasonic signals produced by laboratory made polyethylene (PE) samples an extruded-cable joint under high voltage were studied.

The space charge and electric field distribution in dielectric liquids between electrodes are measured by using a Kerr electro-optic system. After DC application for 1 h to nitrobenzene with Al electrodes, the near interface is enhanced factor of 3. In order improve interface, electrode surfaces coated silicon varnish form an electrode/solid insulator interface. greatly improved insulation coating.