نتایج جستجو برای: dirrect current

تعداد نتایج: 777428  

This paper presents a new control method for simultaneous compensation of instantaneous reactive power and current harmonics by parallel active filters (PAFs). Reference compensating currents of PAF are calculated using the subtraction of instantaneous power from its average value. In this way, it is possible omitting high/low pass filter(s) from the control circuit of PAF, which usually result...

D. Azizian M. Bigdeli, M. Ganji

This study presents a modified transient current limiter (MTCL) for mitigation the inrush current of transformers. The MTCL is based on conventional transient current limiter (TCL), which, its configuration is modified to overcome the TCL drawbacks of operation. The proposed MTCL offers lower power losses and voltage/current THD during normal operation mode. It needs only one limiting reactor i...

2014
Wei Wei Xue Peng

Because the power systemload the randomness of the nature, power transmission of AC induction system has the low efficiency. In order to improve the transmission efficiency,the transmission efficiency influenced factors of the system is analyzed. Based on the current source power transfer system, DC/DC circuit for dynamic adjustment method is proposed. The method ensures that the transmission e...

پایان نامه :0 1369

در زمان برق دار کردن ترانس قدرت یک جریان گذرا وجود داشته که اندازه آن م است بعضی اوقات چندین برابر جریان اسمی باشد. این پدیده گذرا با حالت خطا)fault(تفاوت داشته و بنابراین رله ها (سیسمتهای حفاظتی) نبایستی عمل کنند و باعث بازشدن مدارگردند. هدف از این پروژه بررسی جریان حمله ای inrush current(پیدا کردن مدل ریاضی آن اندازه جریان ماکزیمم،ثابت زمانی، هماهنگها و)... ودرآخر نوشتن یک برنامه کامپیوتری بز...

Reza Soltani Nasab,

This article has no abstract

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد گرمسار - دانشکده زبانهای خارجی 1389

previous studies have aimed at testing a hypothesis but the present study is data-first research in which researcher tries to form a theory from data rather than the use of data to test a hypothesis. this study aims at exploring teachers perceptions of the strengths and weaknesses of the current syllabus for college preparatory course. eight experienced teachers were selected to collect data du...

Journal: :journal of research in medical sciences 0
hamid nasri mahmoud rafieian-kopaei

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Journal: :physiology and pharmacology 0
parvin zareian neuroscience research center, shaheed beheshti univ.med sci., tehran, iran mahyar janahmadi seyed mohamamd firoozabadi fereshteh motamedi

ion channels are responsible for control of cell function in excitable tissues such as heart and brain and also in organs and tissues traditionally thought to be non- excitable including liver and epithelium. in the present research, the effect of lead (pb2+) on ca2+ -dependent action potential and currents was studied in f77 neuronal soma membrane of helix aspersa. for this purpose, action pot...

Journal: :نشریه علمی - پژوهشی هیدرولوژی کاربردی 0
mahmoud kashefipour shahid chamran university mehdi daryaee shahid chamran university

density or gravity currents have been always one of the main causes for sedimentation along many of the dam reservoirs. so controlling this phenomenon is very important for increasing useful life of such reservoirs. in this research study the effect of a combination of rough bed and obstacle on the control of sedimentary density current has been investigated. experiments were conducted in a til...

2012
Marko Gulin

A microgrid is a part of a distribution network embedding multiple distributed generation systems (mostly nonconventional renewable energy sources like photovoltaic panels, small wind turbines etc.) and storage systems with local loads, which can be disconnected from the upstream network under emergency conditions or as planned. The microgrid concept naturally arose to cope with the penetration...

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