نتایج جستجو برای: Power Quality parameters

تعداد نتایج: 1703331  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند 1388

a significant problem in multicarrier communication systems is the necessity to reduce the value of papr (peak-to-average power ratio) of transmitting signal. in this thesis we study the effect of the system parameters such as coding and modulation types on papr and ultimate ber in a mc-cdma system. in this study we consider fading channel as well as the nonlinearity of transmitter’s amplifier ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم انسانی 1389

rivers and runoff have always been of interest to human beings. in order to make use of the proper water resources, human societies, industrial and agricultural centers, etc. have usually been established near rivers. as the time goes on, these societies developed, and therefore water resources were extracted more and more. consequently, conditions of water quality of the rivers experienced rap...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1391

since its introduction in 1959, translation quality assessment (tqa) has been among the most addressed research topics in translation studies. during recent years, there has been a crucial increase on the study of tqa. various methods have come on scene. although these methods are based on scientific theories, most of them have remained at the level of theory. juliane house’s model is among tho...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه - دانشکده برق و الکترونیک 1390

در سالهای اخیر،اختلالات کیفیت توان مهمترین موضوع می باشد که محققان زیادی را برای پیدا کردن راه حلی برای حل آن علاقه مند ساخته است.امروزه کیفیت توان در سیستم قدرت برای مراکز صنعتی،تجاری وکاربردهای بیمارستانی مسئله مهمی می باشد.مشکل ولتاژمثل شرایط افت ولتاژواضافه جریان ناشی از اتصال کوتاه مدار یا وقوع خطا در سیستم بیشتر مورد توجه می باشد. برای مطالعه افت ولتاژ واضافه جریان،محققان زیادی کار کرده ...

Journal: :amirkabir international journal of electrical & electronics engineering 2015
m. torabian esfahani b. vahidi

an electric arc furnace (eaf) is known as nonlinear and time variant load that causes power quality (pq) problems such as, current, voltage and current harmonics, voltage flicker, frequency changes in power system. one of the most important problems to study the eaf behavior is the choice of a suitable model for this load. hence, in this paper, a probabilistic three-phase model is proposed base...

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

in the area of automotive engineering there is a tendency to more electrification of power train. in this work control of an induction machine for the application of electric vehicle is investigated. through the changing operating point of the machine, adapting the rotor magnetization current seems to be useful to increase the machines efficiency. in the literature there are many approaches wh...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی 1391

the study of air infiltration into the buildings is important from several perspectives that may be noted to energy and design of hvac systems, indoor air quality and thermal comfort and design of smoke control systems. given the importance of this issue, an experimental and numerical study of air infiltration through conventional doors and windows has been explored in iran. to this end, at fir...

2002
Stefano Quaia Fabio Tosato

The paper proposes a simple approximated method for calculation of voltage sags in an electrical network. Following the general method for symmetrical (three-phase) fault calculations based on the use of the bus impedance matrix of the network, the paper illustrates the construction of a square matrix that, under acceptable assumptions, directly provides voltage drops (sags) at each node of the...

Journal: :amirkabir international journal of electrical & electronics engineering 2014
v. pourahmadi s. valaee

rapid expansions of new location-based services signify the need for finding accurate localization techniques for indoor environments. among different techniques, rss-based  schemes and in particular oneof its variants which is based on graph-based semi-supervised learning (g-ssl) are widely-used approaches the superiority of this scheme is that it has low setup/training cost and at the same ti...

Journal: :journal of operation and automation in power engineering 2014
m. darabian a. jalilvand r. noroozian

in the past few decades, increasing growth of wind power plants causes different problems for the power quality in the grid. normal and transient impacts of these units on the power grid clearly indicate the need to improve the quality of the electricity generated by them in the design of such systems. improving the efficiency of the large-scale wind system is dependent on the control parameter...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید