نتایج جستجو برای: transformer protection scheme

تعداد نتایج: 408229  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی خواجه نصیرالدین طوسی - دانشکده مهندسی برق و کامپیوتر 1391

power transformers are important equipments in power systems. thus there is a large number of researches devoted of power transformers. however, there is still a demand for future investigations, especially in the field of diagnosis of transformer failures. in order to fulfill the demand, the first part reports a study case in which four main types of failures on the active part are investigate...

2011
M. A. Beg G. M. Dhole

Transformer protection is critical issue in power system as the issue lies in the accurate and rapid discrimination of magnetizing inrush current from internal fault current. Artificial neural network has been proposed and has demonstrated the capability of solving the transformer monitoring and fault detection problem using an inexpensive, reliable, and noninvasive procedure. This paper gives ...

In this paper, a new method has been presented for differential protection of power transformers.  In this approach, chaotic method has been used for distinguishing of inrush current from internal fault current of the transformer. The proposed algorithm has been designed based on analysis of harmonic components of the differential current of the transformer due to internal faults and inrus...

Journal: :Appl. Soft Comput. 2011
Soumya R. Mohanty V. Ravikumar Pandi Bijaya K. Panigrahi Nand Kishor Prakash K. Ray

The decision of digital distance relay is very important for making the protection scheme in the transmission system more reliable. As the current signal is taken from the output of the current transformer, the distortion introduced by the saturation in it affects the performance of the distance relay. In this context proper nonlinear modeling of current transformer is necessary and a suitable ...

Journal: :IEICE Transactions 2008
So Bong Shin Sang-Gug Lee

A differential LC-VCO that adopts a transformer with asymmetric turns-ratio has been proposed. The asymmetric turns-ratio of the transformer leads to the suppression of the AM to FM conversion which is caused by the 1/f noise of the current source transistor. The analysis of the proposed scheme and the improvement in phase noise compare to conventional CMOS LC-VCOs are described. The transforme...

2016
Amir Ghorbani

Distance relays detect transmission line faults and their locations by measuring the voltage and the current signals. Also, phase shifting transformers (PSTs) are used to control the power flow in electrical power systems. PSTs protect transmission lines from thermal overloading, improve the stability of transmission system and control the power flow between different networks. Unfortunately, e...

2009
Chang-Hung Hsu Yeong-Hwa Chang

In this paper, the properties of the physical and chemical materials, such as low loss amorphous HB1 core, high temperature resistance winding and insulation vegetable oil have been developed for use in liquid-immersed power transformer. The measured results of magnetic properties with different ferromagnetic materials core were obtained. Considering winding property for operation above 95°C co...

2008
Sukanta Das Gautam Bandyopadhyay

-Protective systems require a faithful reproduction of primary current on the Current Transformer (CT) secondary side. Saturation is a common problem in a steel core CT. Saturation problem causes dreadful effects in the protection systems. This paper presents a simple solution towards detection and compensation of current transformer saturation problems. This paper describes a method in which C...

Low- impedance transformer ground differential relay is a part of power transformer protection system that is employed for detecting the internal earth faults. This is a fast and sensitive relay, but during some external faults and inrush current conditions, may be exposed to maloperation due to current transformer (CT) saturation. In this paper, a new intelligent transformer ground differentia...

2013
Na Wu Yinjing Guo Yongqin Wei Shuxian Fan Xuehua Li

Transformer differential protection may be of malfunction at the emergence of inrush current, and it will affect the normal operation of the transformer. So the paper puts forward a new application of wavelet energy spectrum entropy-neural network theory in transformer microcomputer protection, in which the multi-resolution analysis of wavelet transform and information entropy technology are co...

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