The main function of current transformers is to adapt the high values of the primary current to values suitable for the operation of relay protection devices, i.e. measuring devices. Under normal ...conditions, a current transformer transforms the current in a virtually permanent ratio, and practically without a phase shift, so the secondary current is actually a scaled value of the primary current. However, when a fault occurs in the power system, currents reach high values. As a result, the flux in the core of the current transformer can reach values above the knee of the magnetization characteristic, causing saturation of the current transformer. When saturation occurs, the secondary current is no longer a scaled value of the primary current, but is deformed. Deformation of the secondary current may cause malfunctioning of some relay protection devices. The development of digital relay protection has made it possible to perform software saturation compensation by applying certain algorithms, thus eliminating the negative consequences that saturation of the current transformer causes. In this paper, one of the possible approaches for compensation of saturation is analyzed, which is based on the application of an equivalent scheme and magnetization curve of the current transformer. Two typical approaches have been singled out, which have been analyzed and tested in more detail. Testing was performed in the MATLAB/Simulink.
The public opinion towards war veterans is in many cases controversial. On the one hand, they are respected, treated as heroes and valuable members of society, and their war merits were compensated ...through material, social and symbolical means. On the other hand, they are often marginalized, and their stigmatization is not uncommon: It is most often related to the psychological consequences of war trauma, but also to assumed dubious motives for joining the military (such as improving social and material status, disturbed personality, etc.). It is well-known that self- stigmatization is difficult to bear, so publicly-created negative images, if exaggerated, can have particularly severe consequences on the lives of defenders and veterans. In order to answer that question, an online survey conducted with 749 Croatian veterans from the Homeland War (1991— 1995) sought to fulfill two goals: first, to examine to what extent the veterans adopted the positive and negative images about their population; and second, to determine how it is related to their subjective well-being. The results show that almost all veterans are aware of and emphasize their merits, but they partly accepted negative views of their status. Additionally, it was shown that the mentioned veterans’ problems are not related or are only marginally related to their subjective well- -being. The findings are interpreted in a broader context, taking into account the phenomenon of personal compensation of public (macrosocial) deficits, typical of transitional societies.
Potreba za povećanjem točnosti pozicioniranja servo-pogona bila je poticaj za istraživanje nove metode bez senzora za kompenzaciju toplinskih deformiranja kuglastih vijaka, koja će omogućiti ...predvidivu kompenzaciju izduženja takvih vijaka na temelju prikupljenih podataka. Razvijeni su modeli za predvidivu kompenzaciju toplinskih deformiranja kuglastih vijaka u CNC strojevima, u obliku jednosmjernih višeslojnih neuronskih mreža s unatražnim rasprostiranjem greške (MLP), neuronskih mreža s funkcijom radijalne baze (RBF) i Kohonen mreža. Razvijene su neuronske mreže s različitim strukturama i parametrima učenja, i te su se mreže uspoređivale. Modeli su se procjenjivali prema učinkovitosti mreža. Modeli su se ispitivali s realnim podacima.
Railway traction is a more stochastic heavy load connected system. Due to the usage of ac-dc converters and ac-ac converters, the various power quality issues become the major problems in the ...electric system. This paper presents a review on power quality conditioners suitable for Railway traction based on the configuration, components involved and on the technical and economic considerations. More than 120 publications are listed in the reference for quick review.
U radu autorica razmatra probleme s kojima se susreću profesionalni igrači i klubovi pri jednostranom raskidu ugovora bez opravdanog razloga s obzirom na sankcije koje se izriču onoj strani koja je ...dovela do takvog raskida ugovora. Situaciju usložnuje i čl. 17. FIFA-inog Pravilnika o statusu i transferima igrača koji ne daje zatvorenu listu kriterija temeljem kojih se spomenute sankcije izriču. Nakon analize i kritike slučajeva Webster, De Sanctis i Matuzalem Arbitražnog suda za sport te njihovog komentara s aspekta švicarskog prava, koje je Arbitražni sud za sport u spomenutim slučajevima držao mjerodavnim pravom, autorica zaključuje da postojeća situacija dovodi do pravne nesigurnosti. Zaključno nudi brojna rješenja de lege ferenda.
U ovom je radu predstavljen problem FACTS regulacije napona i kompenzacije jalove snage u distribucijskoj mreži s priključenom vjetroelektranom. Vjetroelektrana je u izvedbi sa stalnom brzinom i ...konstantnom frekvencijom uz korištenje asinkronog generatora pogonjenog nereguliranom vjetroturbinom. Problem je razmatran s obzirom na kratkotrajni (10sekundi), srednjotrajni (10 minuta) i dugotrajni (48 sati) vremenski period odziva varijabli sustava na različite promjene brzine vjetra. S obzirom na promjenjivu brzinu vjetra, vjetroelektrana injektira promjenjivi iznos djelatne i jalove snage u distribucijsku mrežu te time izlaže obližnje potrošače značajnim promjenama iznosa napona. U konvencionalnom pristupu rješavanja problema korištene su poprečne kondenzatorske baterije smještene u čvorištu asinkronog generatora. U FACTS pristupu korišten je ''objedinjeni regulator tokova snaga'' (eng. Unified Power Flow Controller, UPFC) koji je smješten u točki priključenja vjetroelektrane na distribucijsku mrežu. Korištenje FACTS naprave predstavlja pokušaj rješavanja tehničkih pitanja vezanih uz regulaciju napona u čvorištu priključenja vjetroelektrane te uz minimiziranje razmjene jalove snage vjetroelektrane s distribucijskom mrežom.
Engineers encounter the problem of friction in any mechanical system. Friction force is strongly nonlinear and varies considerably while the system is working. In the case of high-precision ...applications friction makes the situation even more complex, as the stick-slip effect occurs near the target position. This paper introduces a pneumatic servo-system for investigation of the behavior of friction near the target position. A new model is proposed which takes the hysteresis loop of the friction also into consideration emphasizing the importance of hysteresis. This paper presents the tensorproduct (TP) based modeling of friction which is suitable for control design. The main advantage of the TP model transformation is that due to its polytopic model form Linear Matrix Inequality (LMI) can be immediately applied to the resulting model to yield controllers with guaranteed performance. The main contribution of this paper is the application of TP model transformation making the identification of friction parameters unnecessary by utilizing directly the measured data itself.
Izvršni menadžeri čine mali postotak zaposlenika kompanije, ali su ujedno i najvažnija skupina zaposlenika. Idealna strategija menadžerskih kompenzacija osigurava zadržavanje najboljih talenata dok ...istodobno privlači nove talente i minimizira stopu zamjene zaposlenika. Kompenzacije izvršnih menadžera sastoje se od osnovne plaće, kratkoročnih i dugoročnih poticaja, beneficija i bonusa. Svrha rada bila je istražiti i analizirati podatke o strukturi i čimbenicima koji utječu na određivanje kompenzacija izvršnih menadžera top pet globalnih brendova. Prikupljeni podaci o visinama kompenzacija izvršnih menadžera odnose se na razdoblje od 2010. do 2015. godine. Odabrani izvršni menadžeri na čelu su kompanija koje su prema Interbrandovoj listi iz 2015. godine rangirane kao najboljih pet globalnih brendova. Počevši od sedamdesetih godina prošlog stoljeća, kompenzacije glavnih izvršnih menadžera u SAD-u eksponencijalno rastu. Omjer između visine plaća glavnih izvršnih menadžera i ostalih zaposlenika iz godine u godinu se povećava. U pojedinim slučajevima glavni izvršni menadžeri zarađuju i više od četiristo puta više od mediana plaće svojih zaposlenika. Analitičari sugeriraju kako bi svaka kompanija trebala poduzeti određene regulatorne akcije, jer bi se implementiranjem različitih mjera određivanja kompenzacija odnos glavnoga izvršnog menadžera i nadzornog odbora učinio transparentniji svim dioničarima kompanije.
SI: Pridobitev lastninske pravice nad nepremičninami je moč družbene skupnosti, da pridobi nepremičnino, tudi brez soglasja njenega lastnika ali uporabnika, za namen javne koristi. Pri tem se ne more ...zanašati na nepremičninski trg, da pridobi zemljišča/nepremičninetam in takrat, ko in kjer jih skupnost potrebuje za javno korist. V veliko državah po svetu mora država oziroma lokalna skupnost najprej poskušati kupiti nepremičnine za javno korist v »dobri veri«, šele nato lahko uporabi institucijo prisilnega odkupa oziroma razlastitve. Prispevek obravnava možne načine pridobitev lastninske pravice na nepremičninah za dosego javne koristi v Sloveniji, kot so prisilni odkup, razlastitev in pridobitev služnosti v javnem interesu, ter vlogo geodeta v teh postopkih.EN: Acquisition of real property is the power of a government to acquire land, also without the consent of its owner or occupant, for the public benefit. In such cases, any government cannot rely on real property markets alone to ensure that land/real property is acquired when and where it is needed. Several countries worldwideassume that the state or local government should attempt to purchase the required real property in good faith before it exercises its power of compulsory acquisition/expropriation. The paper describes various possible ways of real property ownership appropriationwith the stated purpose of establishing public interest, i.e. an expropriation, compulsory acquisition and establishment of easements for public interest in Slovenia. At the end, the possible role the Slovene surveyor in these procedures is discussed.
Low-power switched-mode power supply converters are used in applications where size and efficiency are critical. The buck converter size can be reduced by elimination of the bulky filter capacitor. ...The filtering function of this capacitor can be replaced by an output current ripple compensation circuit. The compensating circuit is applied, based on inductor current measurement and linear amplifier. The proposed compensating algorithm is investigated theoretically by simulation, and verified experimentally.
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