Iskanje po katalogu digitalne knjižnice

Opis: This paper presents a novel sorting algorithm for modular multilevel inverters (MMCs) with integrated batteries, designed to ensure the uninterrupted operation of electric vehicles (EVs) under post-fault conditions. The proposed system structure consists of an MMC with four full-bridge modules per phase, where one module acts as a spinning reserve during normal operation. The algorithm addresses a single switch fault per phase by operating the faulted module in half-bridge mode, ensuring all batteries remain operational and maintaining full power output and battery capacity without any noticeable changes for the vehicle operator. Unlike conventional fault-tolerant strategies that often reduce power output or disable affected modules, the proposed algorithm isolates the faulty switch while preserving system output. This approach avoids derating and eliminates the need for immediate maintenance, enabling the EV to continue operating under fault conditions. Simulation and experimental results validate the effectiveness of the algorithm under a single switch fault scenario, demonstrating its ability to maintain autonomy and consistent power delivery. This work demonstrates a fault-tolerant MMC principle, offering a robust and scalable solution for enhancing reliability and user satisfaction in EV power systems.
Ključne besede: modular multilevel converter, fault tolerance, redundancy, uninterrupted operation, sorting algorithm
Objavljeno v DKUM: 09.04.2025; Ogledov: 0; Prenosov: 3
Celotno besedilo (10,18 MB)

Opis: This paper presents the design of the control of the system using a double DD coil structure. The double DD coil is a layered coil structure that consists of two single DD coils, rotated to each other by 90◦. A large-signal and small-signal model of the proposed IPT system are designed for control synthesis. The small-signal model is derived from the large-signal using harmonic approximation and the extended describing functions (EDF). For the small-signal model, voltage and current control schemes were proposed for the purpose of wireless battery charging. The robustness of the control is tested on a small-scale IPT system using double DD coils and resistive load. The results are evaluated at different reference voltages, currents, loads and coupling coefficients.
Ključne besede: wireless power transfer, double DD coil structure, voltage control, IPT with multiple coils
Objavljeno v DKUM: 28.03.2025; Ogledov: 0; Prenosov: 2
Celotno besedilo (9,50 MB)
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Opis: Namen magistrskega dela je zagotoviti bolj natančno oceno temperature spoja MOSFET-tranzistorja v primerjavi z obstoječim pristopom, kar bo omogočilo izboljšanje zmogljivosti motorskega krmilnika. Ta temperatura predstavlja ključno, vendar nedostopno stanje, ki ga ni mogoče neposredno izmeriti. Zato smo razvili predikcijski algoritem, imenovan opazovalnik, ki na podlagi meritev vhodov oziroma faznega toka in temperature na dostopni točki sistema ocenjuje temperaturo spoja MOSFET-tranzistorja. V ta namen smo načrtali termalni model krmilnika, predstavljen kot ekvivalentno električno vezje, in ga nato validirali z uporabo termalnih simulacij v časovni domeni in meritvami.
Ključne besede: predikcijski algoritem, MOSFET, termalni model, motorni krmilnik, prostor stanj
Objavljeno v DKUM: 27.03.2025; Ogledov: 0; Prenosov: 11
Celotno besedilo (4,24 MB)

Opis: This thesis focuses on improving the simulation, estimation, and accuracy of parameter identification in lithium-ion battery models. The key objective was to enhance a previously developed program by transitioning it to an object-oriented design, making it more efficient, user-friendly, and modular. Additionally, efforts were made to optimize the parameter estimation process by upgrading the cost function used during simulations and integrating real-world battery measurement data, specifically for the LGM50 battery type. The first step in the thesis involved reworking the codebase to an object-oriented structure, which improved not only the code’s clarity but also its extensibility and efficiency. With this change, the program was better suited for future improvements and became more accessible for other users through simplified installation procedures. This was accompanied by the implementation of unit testing to ensure the reliability of the code. Experiments were conducted across a range of discharge rates (from 0.05C to 1C) to evaluate the performance of the model under different conditions. These tests helped to identify trends in how the model responded to changes in operational parameters. Additionally, a dynamic pulse test was performed, which allowed for more precise estimation of the parameters. The results of these tests demonstrated the robustness of the methodology, especially under dynamic conditions. A major innovation introduced in this thesis was the development of a new cost function, which led to noticeable improvements in parameter estimation accuracy, particularly under high discharge rates and when estimating multiple parameters simultaneously. This new cost function proved especially effective in more complex scenarios, where the original cost function struggled to maintain the same level of accuracy. The program’s capabilities were further extended by incorporating real experimental data. Using a constant discharge profile for the LGM50 battery, the results showed some challenges when dealing with real-world data, particularly due to issues in measurement or data preprocessing. Nonetheless, the model consistently produced solutions, although the accuracy was influenced by the quality of the input data. The thesis concludes by highlighting the success of the improvements made, both in terms of the program’s structure and the precision of its estimations. However, it also emphasizes the importance of improving the quality of real-world data to fully leverage the model’s potential in practical applications. This work lays a foundation for future developments in battery modeling, providing a framework that is adaptable for further research and practical use.
Ključne besede: Machine Learning, Lithium-Ion Batteries, Parameter Estimation, Uncertainty Quantification, Real-experimental data
Objavljeno v DKUM: 03.03.2025; Ogledov: 0; Prenosov: 25
Celotno besedilo (5,99 MB)

Opis: Diplomska naloga je nastala v sodelovanju s podjetjem SMT, ki izdeluje tiskana vezja za LED reflektorje, ki se uporabljajo v filmski industriji. Na vsakem vezju je potrebno nastaviti minimalno in maksimalno osvetlitev za LED diode, kar se je do zdaj počelo ročno, proces pa je trajal 5 do 10 minut. Cilj te naloge je narediti napravo, ki bi to naredila samodejno in hitreje.
Ključne besede: LED, reflektor, tok, konfiguracija, samodejno
Objavljeno v DKUM: 06.02.2025; Ogledov: 0; Prenosov: 0