نتایج جستجو برای: transformer

تعداد نتایج: 11481  

2013
Yan Li Longnv Li Yongteng Jing Bo Zhang

In order to analyze the leakage magnetic field and stray loss in power transformer, leakage magnetic field and stray loss in structure parts of a power transformer are calculated by three-dimensional (3-D) non-linear time harmonic finite element method (FEM). The results show that stray loss and loss density in structure parts are large and which may lead to local overheating and affect perform...

2008
Ankireddypalli S. Reddy M. Vijaykumar

Power transformers represent the largest portion of capital investment in transmission and distribution substations. In addition, power transformer outages have a considerable economic impact on the operation of an electrical network. One of the most important parameters’ governing a transformer’s life expectancy is the hot-spot temperature value. Due to under estimation of stray losses in powe...

2010
Vedran Boras Tomislav Bari

In many text books and papers such as [1]-[5], it is possible to find descriptions about shunt fault calculations and about the influence of the three-phase transformer connection Dyn on the fault currents distribution through distribution transformers. In [6] is described a method for digitally simulating a three-phase power system which is subjected to a fault at one location with blown fuse ...

2018
Lefeng Cheng Tao Yu Guoping Wang Bo Yang Lv Zhou

This paper develops a novel dynamic correction method for the reliability assessment of large oil-immersed power transformers. First, with the transformer oil-paper insulation system (TOPIS) as the target of evaluation and the winding hot spot temperature (HST) as the core point, an HST-based static ageing failure model is built according to the Weibull distribution and Arrhenius reaction law, ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تهران 1387

چکیده ندارد.

Journal: :Electr. Notes Theor. Comput. Sci. 2016
Bart Jacobs Fabio Zanasi

This paper establishes a link between Bayesian inference (learning) and predicate and state transformer operations from programming semantics and logic. Specifically, a very general definition of backward inference is given via first applying a predicate transformer and then conditioning. Analogously, forward inference involves first conditioning and then applying a state transformer. These def...

2008

Reliable energy flow is paramount and power transformers are critical, and costly, assets in the grid. As an asset class, power transformers constitute one of the largest investments in a utility’s system. For this reason transformer condition assessment and management is a high priority. In several parts of the world the transformer fleet is operating beyond its design life and with higher ave...

Journal: :IEICE Transactions 2010
Eunil Cho Sungho Lee Jaejun Lee Sangwook Nam

This paper presents a design of a monolithic transformer using bond wires. The proposed transformer structure has several advantages such as high power handling and high efficiency. It shows that the measured insertion loss at the 1.9 GHz range is −1.54 dB (70%), which is higher than the spiral transformer of the same size. Also, it shows a phase error of less than 1 degree. key words: CMOS RF ...

رضائی زارع, افشین , صنایع پسند, مجید , فرهنگی, شاهرخ , محسنی, حسین ,

Based on the Preisach theory in hysteresis, this paper presents a novel transformer core model. Unlike existing mathematical-based hysteresis models, the proposed model is based on a physically correct hysteresis model and can precisely represent the actual behaviors of magnetic materials. In addition, the experimental results of a ferroresonance test of a Voltage Transformer (VT) are presented...

Journal: :international journal of environmental research 2014
b.s. maluckov v. tasić s. alagić s. mladenović j.t. pejković

in this paper are present the results of measurements of magnetic induction at some locationsin city bor (the east serbia) dating from the household electric devices and transformer stations suited near the residental areas. stress is on the extremely low frequent electromagnetic radiation from transformer stations and other high voltage instalations in urban areas. risk of the extremely low fr...

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