نتایج جستجو برای: electric losses

تعداد نتایج: 205160  

Journal: :Physical review letters 2007
Tom G Mackay Akhlesh Lakhtakia

From the fundamental requirement of causality, we derive a rigorous criterion of negative refraction (left handedness). This criterion imposes the lower limits on the electric and magnetic losses in the region of the negative refraction. If these losses are eliminated or significantly reduced by any means, including the compensation by active (gain) media, then the negative refraction will disa...

Journal: :Fuzzy Sets and Systems 2004
Ying-Yi Hong Zuei-Tien Chao Miin-Shen Yang

Estimation of energy loss is an essential task for both operation and planning in electric distribution systems. The energy losses are considered to be uncertain due to measurements. A new method based on fuzzy-c-number clustering and fuzzy multiple linear regression analysis is proposed for developing energy loss formulas to estimate losses in this paper. The proposed method is implemented wit...

Journal: :CoRR 2014
Dariush Fooladivanda G. Mancini Siddharth Garg Catherine Rosenberg

I. INTRODUCTION Flywheel energy storage devices are composed of a spinning composite disk in an low-pressure enclosure designed to contain the debris in the case of operation failure [18]. An electric motor-generator connector is used to convert the electric energy to kinetic energy by applying a torque on the flywheel. The torque can be positive (charge) or negative (discharge). The flywheel l...

2007
Mark I. Stockman

From the fundamental requirement of causality, we derive a rigorous criterion of negative refraction (left-handedness). This criterion imposes the lower limits on the electric and magnetic losses in the region of the negative refraction. If these losses are eliminated or significantly reduced by any means, including the compensation by active (gain) media, then the negative refraction will disa...

2012
José Alberto Sá Brígida Rocha Arthur Almeida José Ricardo Souza

Weather patterns recognition is very important to improve forecasting skills regarding severe storm conditions over a given area of the Earth. Severe weather can damage electric and telecommunication systems, besides generating material losses and even losses of life (Cooray et al., 2007; Lo Piparo, 2010; Santos et al., 2011). In especial for the electrical sector, is strategic to recognize wea...

2008
Johannes V. Gragger Anton Haumer Christian Kral Franz Pirker

This paper presents an approach to calculate the copper and core losses caused by harmonics of the PWM of a voltage source inverter. For the analysis some models of the Smart Electric Drives (SED) library, and additionally, a Modelica library for modeling AC circuits by means of electric time phasors, are used. With the proposed analysis the influence of space phasor PWM signals on the machine ...

2015
Jun Ho Lee Gee Soo Lee Byung Hun Yu Hyun Chul Kim Kyu Sik Kim Bong Hyun Lee

In this paper, electro-magnetic design and thermal analysis of wheel hub motors, incorporated into the hub of a wheel and driven it directly, of electric vehicles were performed by using analytical and CFD methods. Since thermal management impacts the continuous power capability of electric machines, thermal analysis coupled electro-magnetic analysis are needed to reduce size and improve its pe...

Journal: :Medical physics 2012
Jonas Andersson Erik Johansson Heikki Tölli

PURPOSE The performance of liquid ionization chambers, which may prove to be useful tools in the field of radiation dosimetry, is based on several chamber and liquid specific characteristics. The present work investigates the performance of the PTW microLion liquid ionization chamber with respect to recombination losses and perturbations from ambient electric fields at various dose rates in con...

2014
J. Reena Jenifer P. G Akila

Electric appliances consume electricity when they are in standby mode and sometimes even in off-mode. These "losses" of each appliance individually are not large but the sum over all appliances is no longer negligible. The standby losses of ten households are investigated. The standby power varies from 7 to 134 W and has an average of 40 W. The standby consumption is on average 274 kWh/year, re...

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