Abstract
The altitudinal distribution, breeding density and population size of Tengmalm’s Owl Aegolius funereus was studied in Kopaonik National Park (central Serbia) during the 2011 and 2012 ...breeding seasons. The size of the study area was 24 km2. The
s
urvey method applied was a line transect in combination with stop points and playback of territorial male call. During the two-year research project, 37 territories were located. In Kopaonik National Park, Tengmalm’s Owl males inhabit Norway Spruce Picea abies, mixed Norway Spruce-Silver Fir Abies alba and Norway Spruce-European Beech Fagus sylvatica forests in the altitudinal belt stretching between 1,367 and 1,689 m a.s.l. The breeding density in the studied area was 8.3 territories/10 km2 in 2011 and 7.1 territories/10 km2 in 2012. Total population estimate of Tengmalm’s Owl in Kopaonik National Park is substantially higher than previously assumed, its 42-49 breeding territories making it currently the most important breeding site in Serbia.
Power switching converters have exhibited a wide range of nonlinear behaviors, such as bifurcation and chaos. In this paper, complex bifurcation behaviors in higher order converters with an inductive ...impedance load are analyzed by studying the Floquet multipliers and the switching modes of the system. A single inner current loop controlled Čuk converter is used as an example to account. The period-1 orbit loses its stability by period-doubling and subcritical Neimark-Sacker bifurcations. We find that border collision behavior occurs between period-2 orbits. And then the period-2 orbit enters an unstable torus orbit via Neimark-Sacker bifurcation. The dynamical behaviors of the system are clearly studied under certain conditions. The mechanism of the coexisting phenomenon from subcritical Neimark-Sacker bifurcation is explained. Finally, the chaotic phenomenon from torus breakdown is firstly detected in this higher order switching converter with an inductive impedance load, its characteristics about phase shift to different initial conditions are investigated as well.
This paper presents the comparative analysis between Perturb & Observe (P&O) and Incremental Conductance algorithm for extracting the power from Photovoltaic Array (PVA). Because of nonlinear ...characteristics of PV cell, the maximum power can be extract under particular voltage condition. Therefore, Maximum Power Point Tracking (MPPT) algorithms are used in PVA to maximize the output power. In this paper the MPPT algorithm is implemented using Čuk converter. The dynamics of PVA is simulated at different solar irradiance and cell temperature. The P&O and IC MPPT technique is a direct control method enables ease to implement and less complexity.
Gre za dva lista iz blagajniške knjige Bralnega društva Zagorje za leti 1923 in 1924. Enostavno, natančno, pregledno. In zanimivo, večina izdatkov je šla za naročnine časopisov in revij: za v Trstu ...izhajajoči dnevnik Edinost, za napredno revijo Ženski svet, humoristični list Čuk na palci, predvsem mladim namenjeno Mladiko … Zapisi ob osnovni funkciji zgovorno pričajo še o tedanjih društvenih ciljih – ohranjanju žive slovenske besede v času, ko se je fašistični pritisk nanjo vse bolj stopnjeval. Pa tudi o visoki kulturni zavesti primorskih Slovencev med velikima vojnama.
Most fuel cell electric vehicles require wide voltage-gain DC-DC converters to increase and equalize the relatively low voltage of fuel cell stacks with DC link bus or energy-storage devices, such as ...supercapacitors or batteries. This paper proposes two new non-isolated DC-DC converters suitable for such applications, which can be extended to other electric vehicles as well. The proposed converters combine the main characteristics of both quadratic Boost and Ćuk converters, offering high step-up voltage and control simplicity using only one ground referenced active power switch. Additionally, the proposed topologies present reduced voltage stress across the active power switch when compared to other boost converters. Considerations about the design of the proposed converters will also be presented. Experimental results obtained using a laboratory prototype validate the effectiveness and feasibility of the proposed topologies and its suitability for fuel cell electric vehicles.
Maximum power point tracking using fuzzy logic control Algazar, Mohamed M.; AL-monier, Hamdy; EL-halim, Hamdy Abd ...
International journal of electrical power & energy systems,
07/2012, Letnik:
39, Številka:
1
Journal Article
Recenzirano
► I design and simulate PV water pumping system using MATLAB/SIMULINK. ► I design and simulate a MPPT controller using FLC in MATLAB/FUZZY TOOL BOX/SIMULINK. ► The results validate that MPPT can ...significantly increase the efficiency of energy production from PV. ► The performance of the PV water pumping system compared to the system without MPPT.
This paper proposes an intelligent control method for the maximum power point tracking (MPPT) of a photovoltaic system under variable temperature and insolation conditions. This method uses a fuzzy logic controller applied to a DC–DC converter device. The different steps of the design of this controller are presented together with its simulation. The PV system that I chose to simulate to apply my techniques on it is stand-alone PV water pumping system. Results of this simulation are compared to those obtained by the system without MPPT. They show that the system with MPPT using fuzzy logic controller increase the efficiency of energy production from PV.
DC-DC converters exhibiting minimal input and output ripple are extensively employed across a diverse range of applications. This paper presents a proposed modification to the DC-DC Cuk converter. ...The converter is developed by modifying a conventional Cuk DC-DC converter to exhibit boost characteristics. The DC-DC converters possess the capability to function as versatile units that can be employed in a multitude of applications, ranging from DC-DC conversion to DC-AC conversion (inversion). This paper presents a novel DC-DC converter design that aims to achieve reduced ripple in both input and output currents. By employing the principle of mutual inductance, it is possible to further mitigate the presence of ripple current. The analysis of the impact of mutual inductance on the output voltage and ripple current of the proposed converter has been conducted. The validity of the derived analytical method has been confirmed through both simulated and experimental investigations. The utilization of mutual inductance in the proposed modified Cuk converter has been demonstrated to result in reduced current ripple.
In this article, a new bridgeless Cuk power factor correction converter is presented. The proposed converter is capable of providing full soft switching operation for all semiconductor components in ...the entire line cycle and load variations, only by a single auxiliary switch. The converter operates in discontinuous conduction mode (DCM) that intrinsically provides low input current total harmonic distortion (THD) without any input filter. Despite imposing higher current stress on semiconductors in DCM, the proposed converter achieves high efficiency due to its soft switching operation. The theoretical analysis and operating modes are discussed in detail, and the validity of the analysis is verified by an implemented prototype operating at 200-W output power, 80-V output voltage, and 100-kHz switching frequency, yielding 95.83% efficiency and around 2% THD.
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