نتایج جستجو برای: power line

تعداد نتایج: 873678  

Optimal capacitor placement, considering power system loss reduction, voltage profile improvement, line reactive power decrease and power factor correction, is of particular importance in power system planning and control. The distribution system operator calculates the optimal place, number and capacity of capacitors based on two major purposes: active power loss reduction and return on invest...

H. Rahmanian, M. Khalaj Amirhosseini, S. H Sedighy,

A method for design and implementation of a compact via-less Composite Right/Left-Handed Transmission Line (CRLH TL) is presented. By introducing a new circuit model, the CRLH transmission line behavior is studied versus the parameters variations to achieve the desired characteristic impedance and electrical length. Then a compact quarter wavelength CRLH transmission line with 70 Ω characte...

A new wideband Wilkinson Power Divider which use the nonuniform substrate integrated waveguide (NSIW) method is presented in this paper. This structure utilizes NSIWs instead of the uniform quarter wavelength SIWs in conventional Wilkinson power divider. The proposed structure is analyzed by odd and even mode analysis. The proper NSIW section widths can be extracted by using even mode while the...

Journal: :international journal of electrical and electronics engineering 0
e. abirii m.r. salehiii a. abrishamifariii

active filters have proven to be more effective than passive techniques to improve power quality and to solve harmonic and power factor problems due to nonlinear loads. this paper proposes a control scheme based on the instantaneous active and reactive power. the inverter of this active filter is a three-phase, two-level converter. space vector technique is used as modulators and pattern genera...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علم و صنعت ایران - دانشکده مهندسی برق 1386

در این پایان نامه سعی کرده ایم برای یک سری از ساختارهای خطوط انتقالی که عموما با روش های عددی یا با استفاده از نرم افزارهای full wave حل می شوند، مدلی ساده و در عین حال دقیق ارایه دهیم که می تواند رفتار مدل فیزیکی را از دید پایانه ها به خوبی پیش بینی کند. این ساختار خطوط انتقال میکرواستریپی می شوندکه در بردهای pcb چند لایه به صورت عمود بر هم قرار می گیرند. خطوط مایکرواستریپ عمود برهم به دلیل ...

Background In patients with abnormal uterine bleeding, transvaginal ultrasound (TVS) is the first-line diagnostic approach to exclude endometrial pathology. If a thickened endometrium suggests endometrial pathology, sonohysterography, office hysteroscopy or dilatation and curettage are the second-line tests preferred, depending on availability and on the suspected pathology, to exclude malignan...

Journal: :ISPRS Int. J. Geo-Information 2017
Yong Zhang Xiuxiao Yuan Yi Fang Shiyu Chen

When the distance between an obstacle and a power line is less than the discharge distance, a discharge arc can be generated, resulting in the interruption of power supplies. Therefore, regular safety inspections are necessary to ensure the safe operation of power grids. Tall vegetation and buildings are the key factors threatening the safe operation of extra high voltage transmission lines wit...

Journal: :journal of electric power and energy conversion systems 0

in this paper a comprehensive approach is presented to improve power swings damping based on direct lyapunov method. the approach combines superconducting magnetic energy storage (smes) system with static synchronous compensator (statcom). considering the energy absorption/injection ability of smes, in transient states the combination exchanges both active and reactive powers with power system....

Journal: :international journal of automotive engineering 0
j. mahdavinia molasadra st,vanak sq, tehran, iran a. keshavarz m.h. moshrefi

turbocharging an engine boosts its power by increasing the amount of input air. this task is accomplished by using the exhaust gas to power a turbine which is engaged with a compressor. the variable geometry turbocharger, vgt is a unique turbocharger that the diffuser vane angle can be changed over a wide range of positions. the mathematics of turbomachinery flow analysis is intensive and uses ...

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