In order to deal with power quality problems under distortional and unbalanced load conditions, this paper presents a new control method for a four-wire three-phase unified power quality conditioner ...(UPQC) which is based on instantaneous power p-q theory. The proposed control approach is based on instantaneous power and is optimized by using a self-tuning filter (STF), without using any low-pass filters (LPFs) or phase locked loop (PLL), and without measuring load or filter currents. In this approach, the load and source voltages are used to generate the reference voltages of a series active power filter (APF) and source currents are used to generate the reference currents of a shunt APF. Therefore, the number of times that current is measured is reduced and system performance is improved. The performance of the proposed control approach is evaluated in terms of power factor correction, source neutral current mitigation, load balancing and mitigation of the current and voltage harmonics of distortional and unbalanced loads in a three-phase four-wire system. The results obtained by MATLAB/SIMULINK software show the effectiveness of the proposed control technique in comparison to the conventional p-q method.
Strategija eliminacije harmonika je dobro istražena alternativa tradicionalnoj pulso-širinskoj modulaciji. U ovom radu opisana je strategija eliminacije harmonika asimetričnog višerazinskog invertera ...ujednačenog koraka uz korištenje optimizacije roja čestica čime se eliminiraju harmonici višeg reda uz zadržavanje fundamentalnog napona. Takva metoda može se primijeniti neovisno o broju razina invertera. Kao primjer korišten je inverter s 13 razina kod kojeg se eliminiraju peti, sedmi, jedanaesti, trinaesti i sedamnaesti harmonik. Predloženo rješenje uspoređeno je s dobro poznatom sinusnom pulsno-širinskom modulacijom. Simulacijski rezultati pokazuju prednosti predloženog rješenja. Harmonička distorzija je uspješno poništena te je upravljački signal za asinkroni stroj optimalan. Štoviše, predložena tehnika znatno smanjuje promjene momenta.
A Medley of National Favourites. Things That Make Slovenes ShineSalted with the words of Benedict Anderson: to the Slovene nation, a love of Carniolan sausages, the Vače Situla, accordions and ...gibanica cakes “have an aura of fatality”,Peppered with Raymond Williams: that Carniolan sausages, the Vače Situla, accordions and gibanica reproduce a “structure of national feeling”, andServed with Karl Marx: these grandes dames of the Slovene nation weighas they must on the brains of living Slovenes.
Prvu je fisharmoniku sagradio Anton Haeckel 1821. godine. Osnovna je ideja fisharmonike uporaba slobodnih jezičnjaka kao izvora zvuka, koji su omogućili postupno mijenjanje dinamike zvuka. Harmonij ...je patentirao 1842. godine Alexandre-Fransois Debain (1809. – 1877.). Od tada su se gradili sve veći i složeniji instrumenti pod tim imenom. Danas harmonij pripada glazbenoj povijesti. Fisharmonika kao rani oblik harmonija ostaje kao najljepši, najuporabljiviji oblik tog instrumenta, koji danas živi još samo u tradicionalnoj indijskoj glazbi.
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