With the increase of transmission power in China, heating problem converter transformer resin impregnated paper (RIP) bushings is increasingly serious. In this paper, applying computational fluid dynamics (CFD), using a 3D electromagnetic-fluid-thermal analysis method, and considering heat conduction, convection, radiation effects, temperature field distribution RIP bushing has been simulated; according to simulation results, maximum epoxy above distortion 120°C. Then, verify accuracy rising...

The converter transformer epoxy impregnated paper bushing is a multi-media electrical equipment, and the main materials include internal conductor, external oil, SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> gas, air inside insulation material paper, sheath, fittings. In actual operating, undertaken by harmonic current with large number of high harmonics temperature distribution bushings under waveform needs to be researched. What's...

Extra high-voltage converter transformer resin impregnated paper (RIP) bushing is used as the outlet device of transformer, its safe operation directly related to reliability power system. Under long-term effects high current, strong mechanical stress and abrasion, contact resistance connection structure inside prone deteriorate. When local overheating increases a certain level, insulation performance will decline may lead penetrating discharge. Therefore, it vital develop strategies for...

For the structural characteristics of power transmission equipment such as bushings, plug-in structure is mostly used for current-carrying connections owing to large size and long distance at high voltage levels. The contact element strip key component structure, carrying combined electrical–thermal effect. Its electrical performance important. In recent years, discharge failures caused by overheating failure have occurred from time time. However, there been relatively few studies on...

Abstract The operational temperature regime of a transformer critically influences the electric field topography and interface charge dynamics within oil-pressboard insulation. Employing Kerr electro-optical phenomenon, this manuscript delineates development thermal-modulated mapping apparatus for Empirical analyses on charges under variable thermal conditions revealed following: 1) Within single-oil-spacing model, an escalation in engenders amplified intensity oil, diminished density,...

Gas insulated switchgear (GIS) spacer is required to be of good electrical and mechanical properties ensure high safety reliability. The requirements are stricter for ultra voltage (UHV) GIS under higher pressure. In previous studies, the insulation characteristics epoxy were investigated. But researches on rarely reported. this study, UHV in hydrostatic test simulated with finite-element method. Strain stress distributions along surface Results indicate that maximum appears near flanging...

As the transmission capacity of gas insulated line (GIL) increases, synergistic improvement in dielectric and mechanical strengths GIL insulators is urgently needed for development advanced power systems. Mechanical defects equipment are prone to induce discharges during high voltage operations, which need be mitigated. In this paper, strains on insulator surface measured by fiber Bragg grating (FBG) strain sensors hydrostatic tests. An abnormal change detected near interface between center...

Gas-filled internal crack might appear in thermoset materials like epoxy resin during the equipment manufacturing, which would become a vulnerable local region to initiate electrical tree, thus prone cause insulation failure. The withstand voltage test was carried on samples with artificial cracks based rod-plane electrode arrangement. Simultaneously, surface state variation and tree evolution were observed by an optical microscope conjunction charge-coupled device camera. changes morphology...

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...

UHV DC wall bushing is the only channel connecting valve hall and electric field in converter station. For epoxy - SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> gas composite insulation bushing, main material epoxy/crepe paper core gas. The transient process of establishing for impacted by temperature gradient. In this 3-D has been simulated considering effect heat conduction, convection radiation. simulation results have confirmed...

Transformer oil is an important liquid dielectric of oil-immersed transformers. Moisture and temperature bring a great harm on the transformer insulation. This research was carried out to find influence moisture frequency domain spectroscopy (FDS) characteristics oil. As non-destructive diagnostic technique, FDS technique possesses strong anti-interference ability abundant information, which very suitable for measurement spot. paper focuses relationship between moisture, properties with help...

Converter transformer valve side bushing is an irreplaceable key equipment in the UHVDC transmission project. In process of operation, surface epoxy resin impregnated paper (ERIP) core will produce partial discharge due to insulation defects, and formed arc destroy layer, which seriously threatens safe stable operation bushing. this paper, ablation experimental platform was built study thermal response characteristics ERIP SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Gas insulated metal enclosed line (GIL) has been widely applied in power transmission system due to its high safety and reliability level. Because of cost saving production excellent mechanical property, tri-post insulator is the key structure insulation GIL. Therefore, safe operation determines strength level Tri-post insulators have characteristic with post zone sphere zone. The thickness width zone, conical degree radius depth insert great influence on electrical field strength. High are...

In GIS disconnector, the pull rod acts as an insulating support for connecting current-carrying conductor and shell. It bears large voltage strong machinery a long time. During assembly live operation, may be damaged, various defects appear inside outside rod, which affects stable operation of GIS. order to study defects' influence on insulation performance three-dimensional model disconnector was established in this paper. The electric field distribution isolating switch under normal...

In the actual operation, converter transformer valve side bushings are subjected to high voltages and large current loads with number of harmonics simultaneously. our previous papers, using 3‐D electromagnetic‐fluid‐thermal coupling analysis method, temperature distribution a bushing was researched, heating dissipation characteristics were analyzed. However, electric field is affected by gradient inside bushing. Related researches about electro‐thermal rare most concentrated on single factor...

Gas insulated metal enclosed transmission line (GIL) is widely used in power because of its prefect security and reliability. Tir-post insulator one the most important component GIL which supports insulation structure. However, defects tri-post will distort electric field distribution, weakened insulation, even cause failure. The safety be threatened by defects. So it necessary to analyze effect law electrical distribution defects, focus on severe place need avoid production process. In this...

Transformer resin impregnated paper(RIP) bushing has been widely applied in power transmission system as a vital part of transformer. The performance is important to the reliability level and stability system. However, voltage increases, heating problem paper increasingly serious. In this paper, 3-D electromagnetic-fluid-thermal method was proposed by applying computational fluid dynamics(CFD) analysis. influence thermal conduction, radiation convection heat transfer were taken into account...

The development of advanced dielectric materials with high thermal conductivity is crucial importance in modern electronic and power equipment systems. Herein, multilayer graphene nanosheets/epoxy nanocomposites enhanced were fabricated by solution blended processes. It was found that the incorporation nanosheets had little impact on thermogravimetric properties epoxy composite but a certain effect glass transition temperature (Tg), which increased 4.63 °C 0.1 wt.% nanosheets. also constant...

Metabolic syndrome has been linked to an increased risk of colorectal cancer (CRC) incidence and mortality, but whether adopting a healthy lifestyle could attenuate the CRC conferred by metabolic remains unclear. The aim study is investigate individual joint effects modifiable health status on mortality in UK population.This prospective included 328,236 individuals from Biobank. An overall was assessed at baseline categorized based presence or absence syndrome. We estimated association score...

Gas insulated metal enclosed line (GIL) has a lot of advantages on electromagnetic environment, current capacity and stability. As for the unique characteristic GIL, mature products GIL are more preferable to high voltage transmission field in some situations. With level increasing, insulation designs have challenges difficulties. The world's first 1100 kV been building China from Suzhou Nantong. In order ensure safety stability this projects, improve reliability electrical insulted system,...

With the development of technology Gas-insulated Metal Enclosed Transmission Line (GIL), GIL is used all over world gradually. Compared with existing overhead lines and cables, has many significant advantages. As it a wide voltage range various installation methods, widely in power system transmission field. In recent years, there have been accidents caused by overheat faults world. Therefore, safe reliable operation great significance. this paper, multi-physics model UHV pipeline...

Gas insulated line (GIL) has been widely applied in power transmission system due to its high safety and reliability level. Because of cost saving production excellent mechanical property, tri-post insulator is the key structure GIL. Therefore, safe operation determines insulation strength level Inappropriate manufacturing incorrect installation will cause defects like metallic particles, protrusions or pits, inner void air-gap on contact surface. As result existence these defects, original...

For a fast changing excitation like lightning impulse voltage which is applied to zinc oxide arrester, its waveform in frequency domain contains many different harmonic components and response the sum of each component. Nevertheless, existing simulation analysis electric power equipment's withstand performance almost doesn't consider effects some materials, varistors, whose permittivity vary with frequency. Moreover, IEC, test arrester's polymeric house without varistors or transformer oil...