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1.
Experimental validation of a thermo-electric model of the photovoltaic module under outdoor conditions
Klemen Sredenšek, Bojan Štumberger, Miralem Hadžiselimović, Sebastijan Seme, Klemen Deželak, 2021, original scientific article

Abstract: An operating temperature of the photovoltaic (PV) module greatly affects performance and its lifetime. Therefore, it is essential to evaluate operating temperature of the photovoltaic module in different weather conditions and how it affects its performance. The primary objective of this paper is to present a dynamic thermo-electric model for determining the temperature and output power of the photovoltaic module. The presented model is validated with field measurement at the Institute of Energy Technology, Faculty of Energy Technology, University of Maribor, Slovenia. The presented model was compared with other models in different weather conditions, such as clear, cloudy and overcast. The evaluation was performed for the operating temperature and output power of the photovoltaic module using Root-Mean-Square-Error (RMSE) and Mean-Absolute-Error (MAE). The average RMSE and MAE values are 1.75C and 1.14C for the thermal part and 20.34 W and 10.97 W for the electrical part.
Keywords: dynamic modeling, thermo-electric model, accuracy, measuring device, temperature, output power, PV module
Published in DKUM: 13.11.2023; Views: 233; Downloads: 11
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2.
Proportional-integral controllers performance of a grid-connected solar PV system with particle swarm optimization and Ziegler-Nichols tuning method
Klemen Deželak, Peter Braciník, Klemen Sredenšek, Sebastijan Seme, 2021, original scientific article

Abstract: This paper deals with photovoltaic (PV) power plant modeling and its integration into the medium-voltage distribution network. Apart from solar cells, a simulation model includes a boost converter, voltage-oriented controller and LCL filter. The main emphasis is given to the comparison of two optimization methods-particle swarm optimization (PSO) and the Ziegler-Nichols (ZN) tuning method, approaches that are used for the parameters of Proportional-Integral (PI) controllers determination. A PI controller is commonly used because of its performance, but it is limited in its effectiveness if there is a change in the parameters of the system. In our case, the aforementioned change is caused by switching the feeders of the distribution network from an open-loop to a closedloop arrangement. The simulation results have claimed the superiority of the PSO algorithm, while the classical ZN tuning method is acceptable in a limited area of operation.
Keywords: photovoltaic power plant, optimization, PI controllers, distribution system
Published in DKUM: 10.11.2023; Views: 224; Downloads: 8
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3.
Mesečne energetske statistike : metodološko pojasnilo
Maja Kramžer, Tomaž Božič, Klemen Deželak, 2022

Keywords: raba energije, Slovenije, električna energija, energetika
Published in DKUM: 27.10.2023; Views: 360; Downloads: 10
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4.
Transport sector and hydrogen through the 2022 amendment of the energy statistics regulation
Klemen Deželak, Deja Jurgec, 2022, published scientific conference contribution abstract

Keywords: energy statistics, energy policies, transport sector, hydrogen
Published in DKUM: 27.10.2023; Views: 346; Downloads: 6
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5.
Energy consumption and grid interaction analysis of electric vehicles based on particle swarm optimisation method
Klemen Deželak, Klemen Sredenšek, Sebastijan Seme, 2023, original scientific article

Abstract: The widespread adoption of electric vehicles poses certain challenges to the distribution grid, which refers to the network of power lines, transformers, and other infrastructure that delivers electricity from power plants to consumers. This higher demand can strain the distribution grid, particularly in areas with a high concentration of electric vehicles. Grid operators need to ensure that the grid infrastructure can handle this additional load and prevent overloading and consequences in terms of additional losses. As part of the task, a methodology was developed for the assessment of the electricity consumption of battery electric vehicles in Slovenia. The approach used for the calculation includes the number of electric cars, average consumption, distance travelled and efficiency of the system. Additionally, the results of the modelling approach for an integrated distribution grid model in terms of steady-state simulations are presented. The regular situation of the power losses within the distribution grid is managed together with an optimal result. In this sense, an application of the particle swarm optimisation-based strategy is suggested to minimise reliance on grid systems.
Keywords: electric vehicles, distribution grid, optimisation, power losses
Published in DKUM: 10.10.2023; Views: 244; Downloads: 17
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6.
Kompenzacija kapacitivne jalove moči v SN distribucijskem omrežju : diplomsko delo
Davor Leskovec, 2023, undergraduate thesis

Abstract: Gradnja podzemnih električnih kabelskih vodov je v zadnjem obdobju v porastu. Zaradi procesa prestrukturiranja energetske oskrbe bo kabliranje aktualno tudi v prihodnosti. Pomembno je, da se na problematiko, ki jo ta trend prinaša, pravočasno odzovemo s poenotenimi rešitvami. V diplomski nalogi na začetku predstavimo večanje trenda gradnje kabelskih vodov v distribucijskem podjetju Elektro Ljubljana in problematiko generiranja kapacitivne jalove moči iz kablov. Sledi opis kriterijev, ki nakazujejo na to problematiko, in opis konkretnih pristopov h kompenziranju kapacitivne jalove moči z dušilko. Ugotovitve so strnjene v osnutku tehnične smernice, ki bo v pomoč pri načrtovanju in vzdrževanju srednjenapetostnega elektrodistribucijskega omrežja v Sloveniji.
Keywords: kabliranje, kapacitivna jalova moč, kompenzacija, dušilka
Published in DKUM: 01.06.2023; Views: 576; Downloads: 72
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7.
E-mobilnost na področju Elektra Ljubljana, d. d. : magistrsko delo
Ernest Pavlin, 2022, master's thesis

Abstract: Delo obravnava enega izmed korakov k trajnostnemu načinu življenja družbe, in sicer e-mobilnost. Le-ta omogoča blagodejne učinke na posameznika in okolje. Predstavili smo zakonodajo e-mobilnosti v Sloveniji ter opisali vrste električnih vozil in načine polnjenja. Predstavljeno je podjetje Elektro Ljubljana, d. d., vpliv množične elektrifikacije na distribucijsko omrežje ter načrti gradenj polnilnih postaj v prihodnosti. Opisana je vizija e-mobilnosti v Sloveniji. Prikazani so realni podatki javnih polnilnih postaj podjetja Elektro Ljubljana, d. d. Sledijo scenariji, kjer uporabniki naredijo različne razdalje z BEV in PHEV ter podatki polnjenj le-teh. V zadnjem podpoglavju so prikazani izračuni porabe in primerjava električnih osebnih BEV in PHEV od 2015 do 2021 v Sloveniji.
Keywords: elektromobilnost, polnilna postaja, električna vozila, porabljena električna energija
Published in DKUM: 12.01.2023; Views: 742; Downloads: 108
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8.
Model NN omrežja s priključenimi sončnimi elektrarnami : diplomsko delo
Anže Podlesnik, 2022, undergraduate thesis

Abstract: V diplomskem delu je predstavljena analiza dela nizkonapetostnega omrežja, natančneje območja transformatorske postaje Vovkova loka. Na začetku dela so opisane toplotne črpalke, in sicer v sklopu trenutnega trenda prehoda ogrevanja gospodinjstev iz konvencionalnih virov na obnovljive vire energije, v sklopu samooskrbe z električno energijo pa so predstavljene sončne elektrarne. Za tem je na kratko predstavljeno elektroenergetsko omrežje. V drugem delu sledita opis transformatorske postaje Vovkova loka in izračun potrebnih podatkov za izvedbo simulacije v programskem paketu Matlab/Simulink. Na koncu je predstavljena validacija računalniškega modela in različne simulacije primerov dodatnih obremenitev omrežja.
Keywords: model transformatorja, distribucijsko omrežje, modeliranje, sončna elektrarna, toplotna črpalka
Published in DKUM: 18.11.2022; Views: 843; Downloads: 148
.pdf Full text (2,56 MB)

9.
Analiza vpliva elektromobilnosti na elektroenergetski sistem
Urban Gabrijel, 2019, undergraduate thesis

Abstract: Namen diplomske naloge je s pomočjo najnovejše literature, raziskav in računskih analiz predstaviti situacijo na področju električnih vozil ter omrežne infrastrukture. Pri uvajanju električnih vozil lahko posledično prihaja do preobremenjevanja omrežja. Da bi pridobili celostno sliko, smo v nalogi predstavili vpliv modernizacije z električnimi vozili na elektroenergetski sistem. Glavni cilj diplomske naloge je prikazati, kolikšen vpliv imajo električna vozila na elektroenergetski sistem, vpliv njihove vključitve na okolje in tudi kako zmanjšati preobremenitve sistema.
Keywords: elektromobilnost, elektroenergetski sistem, distribucijsko omrežje, elektroenergetska bilanca, trg električnih vozil.
Published in DKUM: 22.08.2019; Views: 2126; Downloads: 196
.pdf Full text (2,90 MB)

10.
Tržno orientirano nudenje sistemske storitve procesa za vzdrževanje frekvence v centru vodenja verige HE DEM : diplomsko delo
Matjaž Manfreda, 2019, undergraduate thesis

Abstract: Ključna veličina, ki kaže na ustrezno delovanje EES, je frekvenca. Ker se proizvodnja in poraba električne energije v povezavi (interkonekciji) neprestano spreminjata, se spreminja tudi frekvenca. V primeru večjega odstopanja (napake) frekvence od nazivne vrednosti 50 Hz, se (nemudoma) odzovejo agregati v skladu s točno določenimi pravili. Mehanizma se imenujeta proces za vzdrževanje frekvence in avtomatska rezerva za povrnitev frekvence, kjer se prva izvaja samodejno in neposredno na agregatih (sklop turbina - generator), druga pa na »višjem« - sistemskem nivoju (izvaja ga ELES). V diplomski nalogi bom predstavil možnosti daljinskega upravljanja storitve procesa za vzdrževanje frekvence (PVF) z namenom minimizacije obremenitev agregatov DEM ter možnostjo njihovega optimalnega angažiranja na trgu storitev EES RS.
Keywords: Hidro elektrarna, vzdrževanje frekvence, sistemske storitve, statika.
Published in DKUM: 28.06.2019; Views: 1632; Downloads: 119
.pdf Full text (2,66 MB)

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