نتایج جستجو برای: insulation resistance
تعداد نتایج: 383783 فیلتر نتایج به سال:
thermal barrier coatings (tbcs) are used to provide thermal insulation to the hot section components of gas turbines in order to enhance the operating temperature and turbine efficiency. hot corrosion and thermal shocks are the main destructive factors in tbcs which comes as a result of oxygen and molten salt diffusion into the coating. in this thesis atmospheric plasma spraying was used to dep...
The classic approach for determining insulating resistance by using commercial testers is not reliable for testing different types of insulation, especially for cables with one conductor and nanoelectronic oxide-based devices (nanotransistors). In this paper an alternative low-voltage method for measuring insulation resistance based on strongly increased current sensitivity is proposed. The pro...
the oil-paper insulation is a type of an inexpensive combination insulation system in oil-filled power transformers. in this study the dielectric and strength properties of canola oil and mineral oil impregnated hand-sheet papers were investigated. all hand sheets were made of unbleached bagasse soda pulp with two different freeness levels of 200 ± 25 ml, csf and 400± 25 ml,csf. after drying th...
− Test of insulation resistance is pre-requisite for leakage effect evaluation in many electrical measurements. Especially high resistance measurement at low working voltage is often required for evaluation of high precision measurement system. The high resistance measurement at low voltage level with portable hand-set is a challenging task. Here we suggest a simple and convenient method to mea...
The number and diameter of strands to minimize loss in a litz-wire transformer winding is determined. With fine stranding, the ac resistance factor can be decreased, but dc resistance increases as a result of the space occupied by insulation. A power law to model insulation thickness is combined with standard analysis of proximity-effect losses to find the optimal stranding. Suboptimal choices ...
Early detection of avalanche breakdown in an embedded planar capacitor dielectric is addressed in this paper. These failures were observed during accelerated temperature and voltage aging of embedded planar capacitors. At the time of avalanche breakdown there was a sharp drop in the value of insulation resistance. There was no trend in the values of insulation resistance before failure, making ...
Clothing thermal insulation and moisture vapour resistance are the two most important parameters in thermal environmental engineering, functional clothing design and end use of clothing ensembles. In this study, clothing thermal insulation and moisture vapour resistance of various types of clothing ensembles were measured using the walking-able sweating manikin, Walter, under various environmen...
Motivated by a need within the aerospace industry to detect and characterize degradation in the insulation of onboard wires, this thesis reports testing of several extant methods and development of novel capacitive sensors. The work focuses on measuring the electrical parameters resistance and capacitance that are directly related to the material parameters conductivity and permittivity, respec...
The thermal insulation market is dominated by petroleum insulations. A gap has been identified for the manufacture of “green” insulations. These insulations must perform to the same levels of heat transfer resistance as their petroleum based counterparts. Modern petroleum derived insulations can be carcinogenic, toxic to manufacture and release toxins as they degrade. The majority are not envir...
Insulation performance of the dielectrics under extreme conditions always attracts widespread attention in electrical and electronic field. How to improve the high-temperature dielectric properties of insulation materials is one of the key issues in insulation system design of electrical devices. This paper studies the temperature-dependent corona resistance of polyimide (PI)/Al2O3 nanocomposit...
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