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The accumulation of space charge is a major concern in HVDC transmission systems. Although a considerable number of models have been proposed to calculate space charge in thin film and cable samples, there are still many questions that need to be answered, such as effect of defects on conduction and space charge accumulation. In the present paper a simulation model is presented for the calculation...
There is no enough attention about fittings power loss in high voltage transmission line. The traditional method to evaluate the power loss is analytic formula. Because of the irregular construction, the calculation result is not satisfactory. As the AC voltage class rising, the fittings power loss in transmission line is considerable for different fittings materials. To quantitatively analyze the...
When a power apparatus is put into operation, temperature difference always exists in its insulation. As to HVDC insulation system, this temperature gradient may play an important role on the space charge behavior and field distribution. This report summarized our attempts to understand the effects of temperature gradient on space charge and material lifetime. Modified pulsed electro-acoustic (PEA)...
Novel epoxy nanocomposites are fabricated by using 3D interconnected boron nitride nanosheets (BNNSs). The nanocomposites exhibit ultrahigh thermal conductivity enhancement and suppressed dielectric loss at low BNNS loading. Furthermore, the obtained nanocomposites have high electrical insulation performance, showing potential applications in high power LED, advanced packaging materials and microelectronic...
We measured space charge and external circuit current simultaneously in XLPE sandwiched by semi-conductive layers. Space charge accumulation characteristics are important factor to develop a DC power transmission cable. Many research works to investigate the space charge behavior in insulating material like cross-linked polyethylene (XLPE), which is a typical base insulating material for the DC cable,...
High current capability, good integration in urban area and zero external magnetic field are advantages of HTS cables that make them interesting for implementation in the Netherlands. So far experience with HTS cable projects is good, but still limited. Yet there is a need for a proper testing practice. Due to limited operational experience, various aspects remain to be studied. This paper focuses...
The dielectric response of filled high temperature vulcanized (HTV) silicone rubber has been measured in the frequency range 10−4∼100 Hz and in the temperature range 20∼60°C. The complex relative susceptibility of filled HTV silicone rubber was calculated from the measured complex capacitance by removing the effect of infinity frequency capacitance and taking the geometrical sample factor into consideration,...
Spectroscopy is a powerful non-destructive technique that utilizes electromagnetic radiation interaction effect to determine the energy level and structure of atomic or molecular substance. Spectroscopy technique has been successfully used to quantify some power transformer condition monitoring parameters such as Furan and oil interfacial tension value. This paper investigates the feasibility of extending...
In this paper, metamaterials are regarded as a kind of specific medium. The application of three-dimensional electromagnetic field finite element mesh generation methods makes a finite element analysis and calculates the integral to metamaterials and its surrounding spatial structures so as to solve the spatial distribution of meta-materials and its surrounding electromagnetic parameter B and H under...
Ageing of transformer winding insulation is strongly temperature dependent and the problem of temperature rise in transformer during operation has been investigated. However, accurate temperature determination in transformer winding is still a challenge and the location of hottest-spot temperature in transformer also requires further studies. In this study, COMSOL Multiphysics simulation software...
The new online oil sensor system, OilQSens®, enables continuous condition monitoring and power grid protection of high voltage transformers by sensor monitoring of oil aging. The requirements for transformers in the renewable energy rise. Ever more flexibility at a maximum operational reliability and a long life are required of them at the same time, so the requirements for the transformer oil grow...
For the purpose of utilizing decomposition component analysis (DCA) for fault diagnosis of SF6 gas insulated equipment further, SF6 spark decomposition experiments under different spark energies were carried out on the frequency and energy-controllable SF6 spark decomposition test platform. The amount of gaseous by-products of SF6 sparks were measured by GC-MS. The main gaseous by-products of SF6...
We investigate the influence of the type of anti-adhesive films used in the production of polyethylene thin samples on their final chemical composition. For this purpose, LDPE and XLPE films were produced by compression molding at different temperatures and using two different polyethylene terephthalate (PET, Mylar) protective sheets, polyimide (Kapton) film and aluminum (Al) foil. These films were...
Partial discharge (PD) analysis is the most effective method to assess the quality of HVAC cable systems. Regarding HVDC cables, due to the lack of experience and testing tools available, PD tests under DC voltage are performed rarely, and quality control is carried out using AC. However, doubts arise concerning the feasibility of this approach in that PD tests under AC voltage might be significant...
Since GIS bushings are keeping the conducting lines being insulated from the ground and decreasing the intensified electric field strength, its safe and reliable operation are extremely important. However, the complicated structure and high electric field strength are making the structural optimization of bushings necessary. In this paper, the basic principles and process of the newly-presented artificial...
Nano-flllers may act as quantum dots (QDs) in polymer nanocomposites. Permittivity, space charge and treeing were discussed in terms of QDs elsewhere (IEEE ICD 2016, Montpellier and IEEE DEIS 2016, Toronto). In this paper, electrical transport is discussed, when nanofillers behave like QDs. As a result, fillers must become multi-functional traps. In the low electric field, on one hand, they act as...
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