We studied the trapping of positive and negative charges in chemical structures polymers under a high electric field using space charge measurement system. Positive accumulated low-density polyethylene (LDPE), whereas polyimide (Kapton) also ethylene tetrafluoroethylene (ETFE) subjected to electron beam irradiation. To determine charge-trapping sites structures, quantum calculation was carried out Density Function Theory (DFT) with Gaussian 09. The relationship between energy band isosurface...

Surface discharge on dielectric materials seriously restricts the performance of many electrical and electronic systems. Based Pockels electro-optic effect, surface polymeric insulating has been investigated under HVAC in Atmospheric Air. Different polymer such as polyimide (PI), polyethylene terephthalate (PET) polyvinylidene fluoride (PVDF) films are employed. One single cycle sinusoidal with peak value 5 kV duration time 50ms is applied a needle-plate electrode configuration voltage...

We developed a compact system for evaluating the deterioration of insulating materials used in high-voltage dc power apparatuses. The can be simultaneous determination three basic parameters important insulation materials, i.e., conductivity, dielectric constant, and charge accumulation. Charge accumulation, which is detrimental to electrical apparatuses, such as devices, transformers, cables, evaluated using this system. With system, charges accumulated are measured by integrating current...

In this paper, space charge behavior over a large range of electric field and temperature, two kinds epoxy resins are investigated using an improved pulsed electro-acoustic method. Significant influence high temperature on the accumulation in found. Hetero starts to build up at 80 °C under 120 kV/mm for amine-type hardener cured (EP-AM), while 140 60 anhydride-type (EP-AH). The accumulated increases with increasing temperature. maximum enhancement local is 135 123 % EP-AM EP-AH,...

Abstract This study introduces a novel strategy to enhance the high‐temperature electrical performance of silicone elastomer (SE), while ensuring control over its thermal and mechanical properties for SiC device packaging insulation application. For same, ultra‐low‐content inorganic/organic SE nanocomposites are prepared tested (at room temperature 150°C) by grafting polyhedral oligomeric silsesquioxane (POSS) nanofillers doping organic semiconductors. It is found that POSS enhances SE's...

Recently, some accidents in spacecraft due to charging up by irradiation of charged particles have been reported. Some them are caused a surface discharge, which normally takes place plasma environment space. others seem be discharge an accumulation charge the bulk materials relatively high-altitude environment. To investigate materials, authors developing internal measurement system. The dielectric under artificial radioactive rays is observed using developed system, employs so-called...

Investigation of space charge accumulation processes in a chemically cross-linked polyethylene for ac usage (XLPE) and modified XLPE dc (DC-XLPE) at voltage polarity reversal was carried out using pulsed electro-acoustic (PEA) measurement system. We found that huge amount so called packet-like charge, some which partially increased the electric field material to more than twice average applied stress, generated DC stress. It enhanced stress locally sample by almost On other hand, we also not...

This paper reports the effect of DC and pulse wave voltages on space charge characteristics polyimide material for high-frequency insulation. The pulsed electroacoustic method is used to measure distribution inside under with different amplitudes, polarities, frequencies duty ratios. Comparative results show that positive more likely accumulate polyimide. amount accumulated larger than voltages. With frequency, negative a frequency above 50 Hz, while it not 100 Hz maximum distortion electric...

Space-charge characteristics of the pure epoxy resin (EP) and epoxy-based hybrid composites under square pulse waves different polarities frequencies at temperatures are investigated. A specially built high-speed pulsed electro-acoustic (PEA) equipment for high-temperature testing is used. The 40 kV/mm with 25 °C, 50 80 respectively, adopted. findings reveal that a negative electric field greater frequency positive lower can increase space-charge accumulation. At low temperatures, there no...

The relationship between space charge accumulation and breakdown at various temperatures is investigated by observing the formation in low density polyethylene (LDPE) LDPE/MgO nanocomposite material under dc high stress. We have reported, earlier, that, enhancement of electric field LDPE packet-like stress might be a cause its electrical breakdown. Furthermore, it has been found that such does not take place same conditions. Therefore, believed addition MgO to results suppression injection....

Space charge distribution and external current in low density polyethylene (LDPE) under dc high electric field were measured simultaneously using an improved pulsed electro-acoustic (PEA) measurement system. They usually independently different devices. However, to investigate the relationship between space behavior conduction current, it is necessary measure them same sample. Therefore, we developed PEA system simultaneously. In this system, measurements are carried out by alternate...

Relationship between breakdown strength and space charge formation in polyimide film under dc high stress at various temperatures is investigated using pulsed electro-acoustic (PEA) method. Some typical results of the observations show that hetero charges are always found before breakdown. The amount increase with temperature or applied electric field. Since enhancement internal field sample by accumulation not so large, doesn't seem to be an immediate cause However since it observed...

We have observed space charge profiles using the PEA (pulsed electro-acoustic) system in low density polyethylene (LDPE) and cross-linked (XLPE) under high electric dc field to study a relationship between behavior dielectric breakdown. XLPE, which is used as an insulating material of ac power cable, also expected be applied layer DC long distance cable. To apply polymeric materials for it necessary understand "space charge" effect stress. In our previous research works, we found that large...

A positional resolution of space charge measurement system a pulsed electro acoustic (PEA) method is tried to improve using newly designed upper electrode unit and new pulse generator. The improved with good terminator contribute reduce the inductance it results in noise. Moreover, order apply voltage sample efficiently adopted generator, diameter was made be small. In PEA measurement, we have take so-called 'reference' signal, which used for deconvolution data processing get an accurate...

Relationship between breakdown strength and space charge formation in polyimide film under dc high stress at various temperatures is investigated using pulsed electro-acoustic (PEA) method. Polyimide films are used for electric electronic devices as insulating materials. They demanded to show a good performance condition like temperature, with humidity. Furthermore, since the material expected be much thinner, characteristic one of important factors estimate material. On other hand,...

For an insulation layer of a DC power transmission cable, space charge properties various insulating materials have been investigated using pulsed electro acoustic (PEA) method. Especially, cross-linked polyethylene (XLPE), which has improved heating resistance by forming bridge between molecular chains low density (LDPE), is expected to be applied the cable. So, performance XLPE under high stress important. In bulk for cables, there remain some chemical residues crosslinking by-product such...

As a long distance DC power transmission cable, XLPE (cross-linked polyethylene) insulated cable is considered to be used. Since the supposed used at high-temperature because large current flows in inner conductor, it necessary estimate performance of insulating material high temperature. Especially, characteristics space charge accumulation and conduction under stress important it. Therefore, has been developed measuring equipment which enable measure distribution external circuit density...

Space charge dynamics of epoxy based micro-nano hybrid composites under DC and square pulse waves different polarities frequencies are investigated. A specially designed high-speed pulsed electro-acoustic (PEA) system is adopted to measure the space distributions prepared samples voltage with positive negative polarity. The electric field 20 kV/mm 40 used. results show that filler addition can suppress accumulation during polarization. Furthermore, it facilitate dissipation accumulated...

This paper reports on the result of space charge evolution in cross-linked polyethylene (XLPE) planar samples approximately 220 µm thick. The measurement technique used this study is pulsed electroacoustic method.

Space charge distributions in multilayered polyimide films under dc high stress was measured using pulsed electro acoustic (PEA) method. Judging from our previous research works, the space accumulated a single layer film electric field is closely related to electrical breakdown. However, there almost no example investigate accumulation characteristics films. Since multi-layered are usually used for printed circuit board of electronic devices or cover motor windings, it necessary properties...

Space charge accumulation behaviors at voltage polarity reversal in cross-linked polyethylene (XLPE) and improved XLPE for dc cable are observed using pulsed electro-acoustic (PEA) method. A huge amount of so called a packet like charge, which was enough to enhance the electric field significantly, is generated reversal, while it not XLPE. It enhanced stress locally sample by almost twice applied average stress. Since packet-like applicable high direct current (HVDC) network line commutate...

Recently, the switching frequency of motors for automotive and railway cars are increased according with innovation power semiconductor technology. When speed is increased, so called "inverter surge voltage" then coating insulating materials degraded due to high voltage phenomena like partial discharge, dielectric heating space charge accumulation. Since degradation can lead failure motors, it necessary investigate safety motor drive. While many researches discharge affected on windings have...

The relationship between an electrical breakdown and a space charge accumulation in low-density polyethylene (LDPE) cross-linked (XLPE) was investigated under high dc stress using the pulsed electro-acoustic (PEA) measurement system with circuit for external current measurement. It has been found that strongly affects characteristics both materials. However, there is difference how them, but it hard to know why generated. Therefore, we tried measure conduction simultaneously PEA Judging from...

Abstract A molybdenum(IV) aqua ion with sulfur bridges, Mo3OS34+, has been prepared and characterized. An X-ray structure analysis of the iminodiacetato complex from revealed core Mo3(μ-O)(μ-S)2(μ3-S).