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1.
Emulacija dinamične karakteristike baterije z vodenjem večvejnega stikalnega pretvornika
Rok Pajer, 2020, doctoral dissertation

Abstract: Doktorska disertacija obravnava problem emulacij baterijskih paketov za uporabo v razvoju komponent za električna vozila (EV). Predstavljeni so vsi potrebni segmenti, od izbire in identifikacije modelov baterij, ki so primerni za izvajanje v realnem času, razvoja ustreznega pretvornika za emulacijo do razvoja emulacijskega algoritma. Predlagan emulacijski algoritem temelji na kaskadni strukturi, notranjo regulacijo tvorijo ločene regulacijske zanke vejnih tokov na osnovi drsnega režima. Zanke se izvajajo s konstantno stikalno frekvenco, mogoča je implementacija na digitalnih signalnih krmilnikih (DSP). Zaradi uporabe ocene motenj, dobljenih z diskretnimi opazovalniki motenj, je zagotovljeno sledenje drsni ravnini brez efekta drhtenja (angl. chattering). Tokovni regulatorji si delijo skupno referenco toka, zagotovljena je enakost tokov in dinamik, kar omogoča redukcijo sistema več vej pretvornika na sistem 2. reda. Zunanjo regulacijo zagotavlja napetostni regulator, ki ima vključen model emulirane baterije, kar omogoča replikacijo obnašanja baterije v frekvenčnem področju modela. Predkrmilje izhodnega toka v kombinaciji z opazovalnikom motnje, podobnim kot pri tokovni regulaciji, zmanjša vpliv bremena na obnašanje. Posebno je v nalogi obravnavan problem različnih bremen, predlagana so pravila nastavitve parametrov, ki zagotavljajo stabilnost pretvornika tudi ob priklopu bremen konstantne moči (CPL), ki so glavni porabniki v EV. Delovanje predlaganih algoritmov je potrjeno s simulacijami in z eksperimentalnim vezjem.
Keywords: električna vozila (EV), emulacije baterij, vodenje v drsnem režimu, opazovalnik motnje, predkrmiljenje izhodnega toka, bremena konstantne moči (CPL)
Published: 01.10.2020; Views: 289; Downloads: 58
.pdf Full text (4,71 MB)

2.
Načrtovanje in izdelava prototipa sistema/naprave sledenja soncu
Domen Gošek, 2020, master's thesis

Abstract: Magistrsko delo zajema celoten proces razvoja prototipa solarno sledilnega mehanizma, tako na strojnem, programskem in električnem nivoju. Opisani so postopki razvoja in solarno sledilni algoritmi. Prototip je fizični sistem, ki s svojim algoritmom sledi sončni trajektoriji po časovni referenci. To pomeni, da za sledenje potrebuje 4 podatke in sicer: zaporedna številka dneva v letu, ure, minute in geografsko širino. Po zaključenem procesu razvoja je sledilo zbiranje in analiza rezultatov. Rezultate so podajali testi.
Keywords: Solarni sledilnik, sončna celica, časovno sledenje, mikrokrmilnik, koračni motor
Published: 04.03.2020; Views: 369; Downloads: 67
.pdf Full text (2,45 MB)

3.
Analytical modelling of achieving energy efficiency with green walls
Dejan Tasić, 2019, master's thesis

Abstract: In the last years, energy efficiency has become an important issue for the EU and Slovenia, who both strive for more sustainable use of energy in buildings. As an innovative approach to such matter, green walls are vertical structures that can serve both as a façade or an insulation layer as well as an aesthetic design for building application. This thesis contains calculated annual heat (transmission) losses through different wall assemblies with and without a constructed green wall in front of them. The goal is to compare values of heat losses between those wall assemblies and the explanation of such results which will determine if green walls present a viable energy-efficient structure for buildings.
Keywords: energy efficiency, green wall, heat losses, modelling
Published: 18.11.2019; Views: 707; Downloads: 66
.pdf Full text (3,83 MB)

4.
Kvantno računalništvo in Groverjev algoritem
Tinkara Marčec, 2018, master's thesis

Abstract: Magistrsko delo obravnava teoretičen pristop k razumevanju kvantnega računalništva in opisuje kvantni algoritem kot primer uporabnosti hitro se razvijajočega področja. Delo je razdeljeno na štiri dele. V prvem delu je podrobneje opisana matematična podlaga, potrebna za razumevanje kvantnega računanja, ki obsega kompleksna števila, vektorske prostore in razširitve ter linearne transformacije. Drugi del opisuje fizikalne osnove in temeljne definicije ter razlage kvantne mehanike, iz katere se razvija področje kvantnega računalništva. Kvantni mehaniki sledi poglavje kvantnega računalništva, v katerem so predstavljeni osnovni koncepti in elementi, s katerimi je možno graditi kvantne algoritme. Predstavljen je tudi model kvantnega računanja, katerega se poslužujejo raziskovalci in razvijalci na področju odkrivanja novih kvantnih algoritmov. V zadnjem delu magistrske naloge je opisan Groverjev algoritem, eden izmed prvih kvantnih algoritmov, ki prikazuje uporabnost kvantnega računalništva v prihodnosti.
Keywords: linearne transformacije, kvantno računalništvo, kubit, kvantna vrata, kvantno vezje, Groverjev algoritem
Published: 08.01.2019; Views: 545; Downloads: 90
.pdf Full text (653,07 KB)

5.
Avtomatizacija testiranja stanja li-ion baterij
Slavko Brečko, 2018, master's thesis

Abstract: V okviru magistrskega dela je predstavljeno načrtovanje ter izdelava testnega sistema litij-ionskih baterij. Na kratko je opisana litij-ionska baterija ter metode, po katerih lahko ocenjujemo zdravje (State Of Health, SOH) baterije. Po predstavljeni izbrani metodi in izdelavi simulacijskega modela sledi meritev odziva realne baterije in prikaz načrtovanja ter izdelave vezja. Nato je opisana programska oprema vezja ter izdelava ocenjevalnega orodja. Na koncu so prikazane karakteristike realnih baterij.
Keywords: testiranje, litij-ionske, baterije, modeliranje, merilno vezje, karakteristika baterije
Published: 29.05.2018; Views: 868; Downloads: 146
.pdf Full text (5,05 MB)
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6.
Finite element modelling of a field-sensed magnetic suspended system for accurate proximity measurement based on a sensor fusion algorithm with Unscented Kalman Filter
Amor Chowdhury, Andrej Sarjaš, 2016, original scientific article

Abstract: The presented paper describes accurate distance measurement for a field-sensed magnetic suspension system. The proximity measurement is based on a Hall effect sensor. The proximity sensor is installed directly on the lower surface of the electro-magnet, which means that it is very sensitive to external magnetic influences and disturbances. External disturbances interfere with the information signal and reduce the usability and reliability of the proximity measurements and, consequently, the whole application operation. A sensor fusion algorithm is deployed for the aforementioned reasons. The sensor fusion algorithm is based on the Unscented Kalman Filter, where a nonlinear dynamic model was derived with the Finite Element Modelling approach. The advantage of such modelling is a more accurate dynamic model parameter estimation, especially in the case when the real structure, materials and dimensions of the real-time application are known. The novelty of the paper is the design of a compact electro-magnetic actuator with a built-in low cost proximity sensor for accurate proximity measurement of the magnetic object. The paper successively presents a modelling procedure with the finite element method, design and parameter settings of a sensor fusion algorithm with Unscented Kalman Filter and, finally, the implementation procedure and results of real-time operation.
Keywords: accurate proximity measurement, sensor fusion algorithm, Unscented Kalman Filter, finite element modelling
Published: 22.06.2017; Views: 717; Downloads: 266
.pdf Full text (9,23 MB)
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7.
Optimal robust motion controller design using multi-objective genetic algorithm
Andrej Sarjaš, Rajko Svečko, Amor Chowdhury, 2014, original scientific article

Abstract: This paper describes the use of a multi-objective genetic algorithm for robust motion controller design. Motion controller structure is based on a disturbance observer in an RIC framework. The RIC approach is presented in the form with internal and external feedback loops, in which an internal disturbance rejection controller and an external performance controller must be synthesised. This paper involves novel objectives for robustness and performance assessments for such an approach. Objective functions for the robustness property of RIC are based on simple even polynomials with non-negativity conditions. Regional pole placement method is presented with the aims of controllers% structures simplification and their additional arbitrary selection. Regional pole placement involves arbitrary selection of central polynomials for both loops, with additional admissible region of the optimized pole location. Polynomial deviation between selected and optimized polynomials is measured with derived performance objective functions. A multi-objective function is composed of different unrelated criteria such as, robust stability, controllers' stability and time performance indexes of closed loops. The design of controllers and multi-objective optimization procedure involve a set of the objectives, which are optimized simultaneously with a genetic algorithm - Differential evolution.
Keywords: disturbance observer, DOB, uncertainty systems, optimal robust control, multi-objective optimization, differential evolution
Published: 15.06.2017; Views: 648; Downloads: 278
.pdf Full text (2,22 MB)
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8.
Quasipolynomial approach to simultaneous robust control of time-delay systems
Nikolaj Semenič, Andrej Sarjaš, Amor Chowdhury, Rajko Svečko, original scientific article

Abstract: A control law for retarded time-delay systems is considered, concerning infinite closed-loop spectrum assignment. An algebraic method for spectrum assignment is presented with a unique optimization algorithm for minimization of spectral abscissa and effective shaping of the chains of infinitely many closed-loop poles. Uncertainty of plant delays of a certain structure is considered in a sense of a robust simultaneous stabilization. Robust performance is achieved using mixed sensitivity design, which is incorporated into the addressed control law.
Keywords: time-delay systems, simultaneous robust control, algorithm
Published: 15.06.2017; Views: 502; Downloads: 285
.pdf Full text (2,32 MB)
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9.
An ℋ∞ optimal robust pole placement with fixed transparent controller structure on the basis of nonnegativity of even spectral polynomials
Andrej Sarjaš, Rajko Svečko, Amor Chowdhury, original scientific article

Abstract: This paper presents the synthesis of an optimal robust controller with the use of pole placement technique. The presented method includes solving a polynomial equation on the basis of the chosen fixed characteristic polynomial and introduced parametric solutions with a known parametric structure of the controller. Robustness criteria in an unstructured uncertainty description with metrics of norm ℋ∞ are for a more reliable and effective formulation of objective functions for optimization presented in the form of a spectral polynomial with positivity conditions. The method enables robust low-order controller design by using plant simplification with partial-fraction decomposition, where the simplification remainder is added to the performance weight. The controller structure is assembled of well-known parts such as disturbance rejection, and reference tracking. The approach also allows the possibility of multiobjective optimization of robust criteria, application of mixed sensitivity problem, and other closed-loop limitation criteria, where the common criteria function can be composed from different unrelated criteria. Optimization and controller design are performed with iterative evolution algorithm.
Keywords: optimal robust controller, optimization, algorithm
Published: 15.06.2017; Views: 483; Downloads: 292
.pdf Full text (3,03 MB)
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10.
Tehnični in ekonomski del vrednotenja investicije v izgradnjo male hidroelektrarne Belca II
Žiga Papić, 2017, master's thesis

Abstract: Magistrsko delo obravnava tehnični in ekonomski del vrednotenja investicije v izgradnjo male hidroelektrarne. Tako je cilj magistrskega dela ugotoviti, ali ima reka Belca dovolj energetskega potenciala za investicijo v izgradnjo male hidroelektrarne. Na podlagi izmerjenega bruto padca in razpoložljivega pretoka vode je izveden preračun vseh glavnih sestavnih elementov male hidroelektrarne. Namen zaključnega dela je tudi ugotoviti, kako perspektivna je izgradnja male hidroelektrarne iz ekonomskega vidika. Na podlagi investicijskega vložka in obratovalnih stroškov je izvedena analiza upravičenosti investicije pri različnih odkupnih cenah električne energije. Podani so napotki potencialnemu investitorju, pri kateri odkupni ceni električne energije je realizacija projekta smiselna.
Keywords: male hidroelektrarne, reka Belca, hidropotencial, ekonomska analiza, neto sedanja vrednost
Published: 22.03.2017; Views: 1202; Downloads: 37
.pdf Full text (2,81 MB)

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