1. Contactless determination of a permanent magnet’s stable position within ferrofluidMislav Trbušić, Anton Hamler, Viktor Goričan, Marko Jesenik, 2022, original scientific article Abstract: The paper deals with the contactless detection of a rod permanent magnet’s position within
a ferrofluid. The working principle of the proposed approach is grounded on the solenoidal nature of
the field lines. For the line detection technique analyzed in this article, where the magnetic field is
scanned along the line parallel to the magnet’s axial direction, the center of the magnet corresponds
to the point on the line where the radial component of the magnetic field vanished. The concept
introduced here was evaluated numerically, where the results showed a promising perspective for
the technique to be employed in practice. In contrast to the X-ray or Vernier-caliper-based technique,
the one proposed here is somewhat more suitable for employment in applications where simplicity
and robustness are of vital importance.
Keywords: permanent magnet, levitation, ferrofluid, magnetic sensor, magnetic field, finite element method, FEM
Published in DKUM: 28.03.2025; Views: 0; Downloads: 3
 Full text (42,69 MB)
This document has many files! More... |
2. The approach of using a horizontally layered soil model for inhomogeneous soil, by taking into account the deeper layers of the soil, and determining the model’s parameters using evolutionary methodsMarko Jesenik, Mislav Trbušić, 2025, original scientific article Abstract: A new approach using a horizontally layered analytical soil model for inhomogeneous soil is presented. The presented approach also considers deeper soil layers, which is not the case when simply dividing the area of interest into smaller subareas. The finite element method model was used to prepare test data because, in such a case, the soil parameters are known. Six lines simulating Wenner’s method were used, and their results were combined appropriately to determine the soil parameters of nine subareas. To determine the soil parameters in the scope of each subarea, different optimization methods were used and compared to each other. The results were analyzed, and Artificial Bee Colony was selected as the most appropriate method among those tested. Additionally, the convergence of the methods was analyzed, and Memory Assistance is presented, with the aim of shortening the calculation time. In this study, three-, four-, five-, and six-layered soil models were tested, and it is concluded that the three-layered model is most appropriate. A finite element method model based on the soil determination results was constructed to verify the results. The results of the Wenner’s method simulation in the cases of the test data and final model were compared to confirm the accuracy of the presented method
Keywords: grounding system, soil model, finite element method, differential evolution, artificial bee colony, teaching–learning-based optimization
Published in DKUM: 21.02.2025; Views: 0; Downloads: 3
Full text (6,81 MB) |
3. Izračun elektromagnetnega polja v okolici ozemljitvenega sistema ob udaru strele : magistrsko deloDanilo Osojnik, 2024, master's thesis Abstract: V magistrskem delu smo analizirali električni potencial in napetost koraka na površini zemlje v prisotnosti ozemljitvene mreže. To smo storili tako, da smo najprej določili enoplastni in triplastni model zemlje. Podatke za določitev modelov smo pridobili iz meritev, pri čemer smo uporabili Wennerjevo metodo. Enoplastni model smo določili iz povprečja izmerjenih vrednosti specifične upornosti, medtem ko smo triplastni model določili s pomočjo optimizacijskih metod. Nato smo v programu Flux 3D izdelali različne modele zemlje z ozemljitveno mrežo. Ta je imela različno gostoto in se je nahajala na treh različnih globinah. Na opisanih modelih smo simulirali udar strele in analizirali potencial na površini in v globini zemlje. Iz potencialov smo izračunali napetost koraka in jo za obravnavane scenarije med seboj primerjali.
Keywords: Prenapetosti, ozemljitvena mreža, potencial, napetost koraka
Published in DKUM: 02.07.2024; Views: 145; Downloads: 101
Full text (8,65 MB) |
4. REKONSTRUKCIJA VALJČNE PROGE 800 V ŠTORE STEEL : diplomsko deloGregor Pusar, 2024, undergraduate thesis Abstract: Diplomsko delo obravnava rekonstrukcijo valjčne proge 800 v podjetju Štore Steel, ki jo je izvedlo podjetje ETRA, d. o. o. V osnovi gre za krmiljenje asinhronskih motorjev, ki so ostali nespremenjeni od začetka delovanja proge. Proga 800 uporablja 16 asinhronskih motorjev, pri čemer je prvotno en pretvornik krmilil osem asinhronskih motorjev (pretvornik ASEA tip »YRYB«), tj. pretvornik ASEA tip »YRYB«, ki je bil v uporabi ob zagonu stroja. Pretvornik ASEA tip »YRYB« je bil sprva najustreznejša rešitev, nato pa se je pojavila težava z vzdrževanjem, saj je bila elektronika draga in težavna za pridobiti, predvsem zaradi pomanjkanja rezervnih delov. Prva faza prenove je vključevala postopno demontažo obstoječih pretvornikov ASEA in namestitev pretvornikov SIMOVERT MASTERDRIVES Vector Control. Ta izvedba je težavna za vzdrževanje, saj če odpove samo en segment (DC-link), so štirje motorji v napaki. Kljub temu da je ta izvedba težavna za vzdrževanje, je bila v tistem času najboljša možna rešitev. Prav zaradi tega je sledila nadaljnja zamenjava za Sinamics S120, ki krmili štiri asinhronske motorje. Ta izvedba je prav tako predstavljala izzive za vzdrževanje, saj je odpoved enega segmenta (DC-link) povzročila napako pri štirih asinhronskih motorjev, podobno kot pri SIMOVERT MASTERDRIVES Vector Control. Končna faza prenove je vključevala uporabo pretvornikov Sinamics G120C. Vsak asinhronski motor je dobil svoj pretvornik, kar je omogočilo izboljšano vzdrževanje in boljšo diagnostiko. Morebitna okvara enega pretvornika ni več vplivala na celotno proizvodnjo in proizvodni proces. Delo prav tako podrobno opisuje postopek optimizacije pretvornika Sinamics G120C z uporabo programskega orodja STARTER.
Keywords: asinhronski motor, optimizacija, regulacija, Siemens Sinamics G120C, Štore Steel
Published in DKUM: 01.07.2024; Views: 265; Downloads: 92
Full text (7,33 MB) |
5. Numerično določanje karakteristik sinhronskega motorja z različnimi velikostmi trajnih magnetov : magistrsko deloDavor Car, 2024, master's thesis Abstract: Magistrsko delo obravnava osnovni pristopa k modeliranju in konstruiranju sinhronskega motorja s trajnimi magneti s pomočjo računalniškega programa Flux. Izvedena je numerična analiza konstrukcijskih parametrov trajnih magnetov na navorno karakteristiko motorja. Analiza zajema vpliv različnih dimenzij in postavitev magnetov na vrednost valovitosti navora in razmerje navora proti volumnu trajnih magnetov. Rezultati nakazujejo, da je s predstavljenim računalniško podprtim pristopom, moči že v fazi načrtovanja motorja izbrati najustreznejše dimenzije za doseganje čim boljšega izkoristka z želeno navorno karakteristiko.
Keywords: Elektromotor, sinhronski stroj, sinhronski motor s trajnimi magneti, STSM, modeliranje, Flux, MKE, metoda končnih elementov, navitje, trajni magneti, valovitost navora, razmerje navora na volumen
Published in DKUM: 01.07.2024; Views: 136; Downloads: 56
Full text (1,87 MB) |
6. Innovative approach for the determination of a DC motor’s and drive’s parameters using evolutionary methods and different measured current and angular speed responsesMarko Jesenik, Miha Ravber, Mislav Trbušić, 2024, original scientific article Abstract: The determination is presented of seven parameters of a DC motor’s drive. The determination was based on a comparison between the measured and simulated current and speed responses. For the parameters’ determination, different evolutionary methods were used and compared to each other. The mathematical model presenting the DC drives model was written using two coupled differential equations, which were solved using the Runge–Kutta first-, second-, third- and fourth-order methods. The approach allows determining the parameters of controlled drives in such a way that the controller is taken into account with the measured voltage. Between the tested evolutionary methods, which were Differential Evolution with three strategies, Teaching-Learning Based Optimization and Artificial Bee Colony, the Differential Evolution (DE/rand/1/exp) can be suggested as the most appropriate for the presented problem. Measurements with different sampling times were used, and it was found out that at least some measuring points should be at the speed-up interval. Different lengths of the measured signal were tested, and it is sufficient to use a signal consisting of the drive’s acceleration and a short part of the stationary operation. The analysis showed that the procedure has good repeatability. The biggest deviation of calculated parameters considering 10 repeated measurements was 6% in case of the La calculation. The deviations of all the other parameters’ calculations were less than 2%.
Keywords: differential evolution, artificial bee colony, teaching-learning based optimization, DC motors, electric drive
Published in DKUM: 26.01.2024; Views: 230; Downloads: 27
Full text (5,41 MB)
This document has many files! More... |
7. Sensitivity Analysis of Hybrid Powertrain Pre-calibration Algorithms : magistrsko deloSimon Šegula, 2023, master's thesis Abstract: Currently, meeting the new fuel consumption and emissions standards is the biggest challenge in the automotive industry. One of the solutions is hybridization of the vehicle’s powertrain. This brings with it larger complexity of the vehicle control unit and its pre-calibration. This thesis explores gear shift map and load point shift map, which are two pre-calibration maps included in the vehicle control unit. More specifically it delves in to how the pre-calibration maps are created and how changing their parameters impacts the fuel consumption of the vehicle. Algorithms and optimization simulations were created and performed using AVL’s tool called the Powertrain system optimizer (PSO) which was created within the MATLAB software.
Keywords: Hybrid electric vehicle, Hybrid powertrain, Gear shift map, Load point shift map, Pre-calibration.
Published in DKUM: 23.11.2023; Views: 393; Downloads: 0 |
8. Avtomatizacija transformatorske postaje 20/0,4 kv Trobni Dol : diplomsko deloAljaž Urek, 2023, undergraduate thesis Abstract: Diplomska naloga opisuje avtomatizacijo distribucijske TP 20/0,4 kV Trobni Dol. V prvem delu je na kratko opisana prednost avtomatizacije TP na splošno. Transformatorska postaja Trobni Dol je na težje dostopni lokaciji, zato se je podjetje Elektro Celje, d. d., odločilo za avtomatizacijo le-te z vgradnjo daljinskega vodenja. Avtomatizacija je mogoča le z upoštevanjem sodobnih standardov in predpisov. V nadaljevanju so prikazani izračuni za določitev opreme postaje in na kratko je predstavljeno dimenzioniranje. Prikazana je tudi oprema, potrebna za želeni rezultat, za zanesljivo in nemoteno oskrbo z električno energijo s čim manjšim človeškim poseganjem v elektrodistribucijski sistem.
Keywords: transformator, avtomatizacija, transformatorska postaja, kratkostične razmere
Published in DKUM: 24.10.2023; Views: 558; Downloads: 128
Full text (2,79 MB) |
9. Računalniško načrtovanje kompenzacijske dušilke jedernega tipa : diplomsko deloPatrick Polajžer, 2023, undergraduate thesis Abstract: V nalogi je predstavljen postopek načrtovanja kompenzacijske dušilke jedrnega tipa. V prvem delu diplomskega dela smo predstavili, kaj sploh je kompenzacijska dušilka, kako deluje, kateri deli jo sestavljajo in pa kje jo sploh uporabljamo. Naredili smo tudi osnovni izračun visokonapetostne dušilke v Matlabu , kjer smo določili osnovne parametre za konstruiranje dušilke. V osrednjem delu naloge smo naredili tudi ekonomsko ceno dušilke ki smo jo predstavili z grafom ki prikazuje ovojno napetost v odvisnosti od cene. Na podlagi dobljenega grafa iz Matlaba smo se odločili, da smo pozneje modelirali ekonomično dušilko v programu FEMM in izračunali njeno induktivnost. V zadnjem delu naloge smo dobljen numerični izračun induktivnosti za ekonomično dušilko primerjali, kako smo ga izračunali v programskem okolju Matlab in FEMM in prišli do ugotovitev da se induktivnost pri istih dimenzijah konstrukcije razlikuje za nekaj procentov to smo probali spremeniti z spreminjanjem debeline zračne reže. Ugotovili smo da lahko uporabljene metode služijo za načrtovanje kompenzacijske dušilke.
Keywords: kompenzacijska dušilka, jedrni tip, načrtovanje, metoda končnih elementov (FEM)
Published in DKUM: 13.10.2023; Views: 558; Downloads: 59
Full text (2,82 MB) |
10. Vpliv razporeditve kablov v kanalu na maksimalno obremenljivost kablovoda : diplomsko deloGoran Vorih, 2023, undergraduate thesis Abstract: V diplomskem delu smo se na kratko dotaknili slovenskega prenosnega omrežja, opisali smo napetostne nivoje slovenskega prenosnega omrežja kot tudi povezavo s sosednjimi sistemi. Predstavili smo statistiko kablovodov v slovenskem elektroenergetskem omrežju, njen pomen in vlogo v ESS. Podrobneje smo se osredotočili na konstrukcijo srednje napetostnega kabla kot tudi na posamezne dele, ki ga sestavljajo. Predstavili smo enožilni in trižilni energetski kabel, univerzalni energetski kabel in trižilni energetski kabel AXAL – TT PRO 12/24 kV, ki smo tudi modelirali v programskem paketu FEMM in naredili temperaturno ter ekonomsko analizo.
Keywords: kabel, temperatura, večžilni kabel, FEMM
Published in DKUM: 27.06.2023; Views: 651; Downloads: 135
Full text (2,59 MB) |
