نتایج جستجو برای: power transformer

تعداد نتایج: 494887  

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...

Journal: :مهندسی قدرت ایران 0
reza shariatinasab university of birjand, iran z ejtemaee university of birjand, iran j gholinezhad university of birjand, iran

power system overvoltages due to switching, lightning and other disturbances are the main problem for designers of the power transformers. once some frequencies of the incoming surges match with some of the natural frequencies of transformer winding, the resonance phenomenon is expected in transformer winding. the resonant overvoltages may destroy the insulation between turns and cause to insul...

One of transient phenomenon that causes the mal-operation of the power transformer differential protection during the energization of a loaded power transformer is the ultra-saturation phenomenon. In this paper, a new model for investigating the ultra-saturation phenomenon during the energization of a loaded power transformer is presented and its effect on the differential protection of the pow...

One of transient phenomenon that causes the mal-operation of the power transformer differential protection during the energization of a loaded power transformer is the ultra-saturation phenomenon. In this paper, a new model for investigating the ultra-saturation phenomenon during the energization of a loaded power transformer is presented and its effect on the differential protection of the pow...

Journal: :journal of operation and automation in power engineering 2007
j. fallah ardeshir a. ajami a. jalilvand a. mohammadpour

this paper proposes a flexible power electronic transformer (fpet) for the application in the micro-grids. the low frequency transformer is usually used at the point of common coupling (pcc) to connect the low voltage grid and utility network to each other. the conventional 50hz transformer results in enhanced low voltage-grid power management system during grid-connected operation. in this pap...

This paper presents a lifetime efficiency index model and a developed crow search algorithm (DCSA) in order to achieve optimal maintenance for the power transformer. Not doing maintenance on the power transformer, resulting in instability of the transmission system and not to supply consistently electric energy in the load points. In other words, deterioration of the transmission system effects...

A. Ebrahimzadeh, M. Mirzaie, M. Sefidgaran,

Reliability of a power system is considerably influenced by its equipments. Power transformers are one of the most critical and expensive equipments of a power system and their proper functions are vital for the substations and utilities. Therefore, reliability model of power transformer is very important in the risk assessment of the engineering systems. This model shows the characteristic...

جلیلیان, علیرضا , عبداللهی, روح اله ,

In this paper, a 24-pulse ac-dc converter is designed, modeled and simulated based on a fork autotransformer to improve power quality indices. The use of autotransformer results in reduced kVA rating of the proposed topology as compared with the transformer based 24-pulse converter. Due to the proper flexibility of the proposed topology, it can be simply utilized in other similar applications. ...

2014
Bi Tian Shu Chen Jin Meng Sun Meng

Risk assessment for power transformer is an important means to guide the condition based maintenance of transformer and enhance the reliability of power system operation, but also to strengthen the power transformer to provide an important basis for quality control. In this paper, an index system for comprehensive evaluation of transformer is put forward and a risk assessment model for power tr...

In this paper, a new model based on the thevenin equivalent circuit for investigating the ultra-saturation phenomenon during the energization of a loaded power transformer is presented and its effect on the differential protection of the transformer is considered. The ultra-saturation phenomenon causes the mal-operation of the power transformer differential protection. So, the description a...

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