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1.
Parameter estimation for the basic Zirka-Moroz history-dependent hysteresis model for electrical steels
Martin Petrun, Ermin Rahmanović, 2025, izvirni znanstveni članek

Opis: History-dependent hysteresis models can potentially describe magnetization curves of all orders accurately. This property is essential for modeling magnetization and power loss in magnetic components subjected to distorted excitation waveforms, which result in complex magnetization patterns such as offset minor loops. The basic Zirka–Moroz history-dependent hysteresis model offers a good balance between the model’s complexity and accuracy. However, estimating the model’s parameters can be challenging. This research provides insight into the parameter estimation procedure for the discussed hysteresis model. Based on the measured first-order reversal curves, the fundamental two-step parameter estimation procedure was employed and analyzed for two non-oriented and one grain-oriented electrical steel types used widely in contemporary electric drives and electromagnetic devices. For each sample evaluated, two sets of parameters were estimated and compared to the reference parameters recommended for non-oriented electrical steels. The performed analysis is essential for gaining a comprehensive understanding of the capabilities, challenges, requirements, and limitations associated with estimating the parameters and performance of the analyzed model for specific electrical steel types.
Ključne besede: history-dependent hysteresis model, grain-oriented electrical steel, magnetic hysteresis, non-oriented electrical steel, parameter estimation, static hysteresis
Objavljeno v DKUM: 30.05.2025; Ogledov: 0; Prenosov: 1
.pdf Celotno besedilo (5,11 MB)

2.
Integrating Multi-Physics Modeling within Multi-Objective Optimization to Enhance the Performance and Efficiency of Permanent Magnet Synchronous Machines : doktorska disertacija
Mitja Garmut, 2025, doktorska disertacija

Opis: This Dissertation focuses on the optimization of an Interior Permanent Magnet (IPM) machine for handheld battery-powered tools, aiming to enhance performance and efficiency. The research integrates multi-physics modeling, including electromagnetic Finite Element Method (FEM) and thermal models, to evaluate machine performance under various operating conditions. The performance is evaluated according to selected Key Performance Indicators (KPIs). Further, different control methods, such as Field Oriented Control and Square-Wave Control, impact the performance significantly and are incorporated into the optimization process. Due to the computational challenges of FEM-based performance evaluations in Multi-Objective Optimization (MOO), this work utilizes Artificial Neural Network (ANN)-based meta-models, to accelerate the optimization process while preserving accuracy. The developed meta-models capture nonlinear machine characteristics from the FEM model. These meta-models are then used to evaluate machine performance through a combination of analytical and numerical post-processing methods. Four MOO scenarios are presented, each aimed at optimizing the cross-sectional design of IPM machines, to enhance performance and efficiency while reducing mass and cost. Additionally, these scenarios modify the machine’s electromagnetic behavior, to ensure better alignment with the selected control method. By comparing the optimization process of Scenario 1, which uses direct FEM-based evaluation without time reduction measures, to the approach incorporating Artificial Neural Network based meta-models, the total number of individual FEM evaluations decreased from 2.35×10^9 to 2.03×10^5, without almost any loss of accuracy. This reduced the computation time from 297 years to 9.07 days on our standard desktop computer. The obtained ANN-base meta-models can be used further for other optimizations without the need for additional FEM evaluations. In all four optimization scenarios, the use of meta-models enabled the generation of a Pareto front of the optimal solutions, leading to improved KPIs compared to the reference design. The highest relative improvement occurred in Scenario 1, where the selected optimized machine design achieved a 30% increase in power density compared to the reference design.
Ključne besede: Interior Permanent Magnet (IPM) Machine, Artificial Neural Network (ANN), Meta-Modeling, Multi-Objective Optimization (MOO), Finite Element Method (FEM), Multi-Physics Modeling, Field Oriented Control (FOC), Square-Wave Control (SWC)
Objavljeno v DKUM: 15.05.2025; Ogledov: 0; Prenosov: 37
.pdf Celotno besedilo (17,79 MB)

3.
Izdelava tehnične dokumentacije za montažno celico za avtomatizirano sestavo tečajev : diplomsko delo
Aleš Dvorjak, 2024, diplomsko delo

Opis: V zaključnem delu smo se lotili izdelave načrta električnih inštalacij in tehnične dokumentacije za avtomatizirano montažno celico. Celica je končna postaja na liniji sestave tečajev v podjetju Turna, d. o. o. Zaključno delo zajema opis delovanja montažne celice, njeno zgradbo, komponente, načrt električnih inštalacij, navodila za varno delo in pomen naprave za proizvodnjo. Podobna montažna celica v podjetju že obstaja, a nova celica vsebuje nadgradnje oz. ima kakšno delovno enoto manj. Načrt električnih inštalacij smo narisali s pomočjo programa Eplan.
Ključne besede: avtomatizacija, montažna celica, načrt električnih inštalacij, tečaji, tehnična dokumentacija
Objavljeno v DKUM: 10.02.2025; Ogledov: 0; Prenosov: 0

4.
Sensitivity analysis of MTPA control to angle errors for synchronous reluctance machines
Martin Petrun, Jernej Černelič, 2025, izvirni znanstveni članek

Opis: This study investigated the sensitivity of maximum torque per ampere (MTPA) control in synchronous reluctance machines (SynRMs) to angle errors, examining specifically how deviations in the reference control trajectory affected performance. Analytical and numerical methods were employed to analyze this sensitivity systematically, including the impact of magnetic saturation. Two MTPA control implementation schemes were evaluated, with torque and current amplitude as the reference variables, using a template SynRM from the open-source simulation tool SyR-e. The results indicated that performance sensitivity to angle errors was moderately low near the MTPA trajectory, allowing for significant angle deviations with minimal performance loss. Although magnetic saturation increased this sensitivity slightly, reducing the allowable error range by up to 25%, the maximum angle deviation for up to 1% of the performance decrease still corresponded to approximately ±3∘ around the MTPA trajectory. The findings of this study suggest potential for simplifying control implementations, reducing component costs through less precise position determination (sensor-based or sensorless), and achieving additional control objectives such as torque ripple reduction.
Ključne besede: control angle error, finite element method, MTPA control, sensitivity to performance decrease, suboptimal operation, synchronous reluctance machines
Objavljeno v DKUM: 07.02.2025; Ogledov: 0; Prenosov: 6
.pdf Celotno besedilo (1,46 MB)

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Razvoj naprave za nanašanje ognjevzdržnega premaza na peščene kalupe za izdelavo centrifugalno litih valjev : magistrsko delo
Denis Marš, 2024, magistrsko delo

Opis: V magistrskem delu je obravnavan razvoj naprave za nanašanje ognjevzdržnega premaza na peščene kalupe, ki se uporabljajo pri proizvodnji centrifugalno litih valjev. Naprava je zasnovana za izboljšanje kakovosti in zanesljivosti proizvodnje valjev, ki so ključni element pri procesih vročega valjanja. Uporaba avtomatiziranega sistema omogoča večjo natančnost pri nanosu premaza in obenem zmanjša potrebo po ročnem delu, kar prispeva k večji varnosti zaposlenih ter manjši možnosti napak, ki so pogosto posledica človeškega faktorja. Poleg tega naprava bistveno pospeši proizvodni proces, saj premazovanje kalupov izvede hitreje kot pri ročnem načinu dela. Naprava vključuje napredne algoritme, ki zaznavajo položaj kalupa in omogočajo natančno prilagajanje gibanja naprave, da se ta samodejno uskladi s položajem kalupa v delovnem območju. Ti algoritmi prav tako omogočajo prilagoditev postopka premazovanja glede na velikost kalupa, kar zagotavlja zaželjene rezultate ne glede na dimenzije kalupa.
Ključne besede: ognjevzdržni premaz, industrija, centrifugalno liti valji, produktivnost, avtomatizacija
Objavljeno v DKUM: 15.01.2025; Ogledov: 0; Prenosov: 22
.pdf Celotno besedilo (10,22 MB)

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Analysis of higher-order bézier curves for approximation of the static magnetic properties of NO electrical steels
Ermin Rahmanović, Martin Petrun, 2024, izvirni znanstveni članek

Opis: Adequate mathematical description of magnetization curves is indispensable in engineering. The accuracy of the description has a significant impact on the design of electric machines and devices. The aim of this paper was to analyze the capability of Bézier curves systematically, to describe the nonlinear static magnetic properties of non-oriented electrical steels, and to compare this approach versus the established mathematical descriptions. First, analytic functions versus measurements were analyzed. The Bézier curves were then compared systematically with the most adequate analytic functions. Next, the most suitable orders of Bézier curves were determined for the approximation of nonlinear magnetic properties, where the influence of the range of the input measurement dataset on the approximation process was analyzed. Last, the extrapolation capabilities of the Bézier curves and analytic functions were evaluated. The general conclusion is that Bézier curves have adequate flexibility and significant potential for the approximation and extrapolation of nonlinear properties of non-oriented electrical steels.
Ključne besede: analytical modeling, anhysteretic curve, applied mathematics, Bézier curve, curve fitting, first magnetization curve, major loop, mathematical modeling, non-oriented electrical steel
Objavljeno v DKUM: 01.02.2024; Ogledov: 382; Prenosov: 29
.pdf Celotno besedilo (4,90 MB)

9.
Modelling of unit differential reversal curves in the G2E hysteresis model
Ermin Rahmanović, Martin Petrun, 2024, izvirni znanstveni članek

Opis: Iron losses represent a crucial factor in the design process of electrical machines. For this reason, it is important to consider adequate hysteresis behavior within models which predict iron losses. A promising hysteresis description is the static hysteresis model developed by the G2Elab research group. It proposes a unique approach of modelling magnetization curves inside the major loop based on the so-called unit differential reversal curves (uDRCs). This work focuses on modelling of the uDRCs. We analyzed the accuracy and identification approaches of several uDRC models, where we compared the established model with simplified solutions with less parameters. Further, we analyzed the impact of individual models regarding identification convergence. Finally, we highlighted which simplified models give the best trade-off between the ease and stability of identification process of parameters, and the accuracy of the hysteresis model.
Ključne besede: static hysteresis model, iron loss, loss surface model, magnetic material, mathematical modelling
Objavljeno v DKUM: 26.01.2024; Ogledov: 214; Prenosov: 30
.htm Celotno besedilo (154,34 KB)

10.
Vodenje asinhronskega stroja s pretvornikom Siemens SINAMICS G120 : diplomsko delo
Žiga Romih, 2023, diplomsko delo

Opis: V diplomskem delu je predstavljeno vodenje asinhronskega stroja s pretvornikom Siemens SINAMICS G120. Najprej sta predstavljeni uporabljena strojna in programska oprema, s pomočjo katerih smo izvedli eksperimentalno analizo. Podrobneje je predstavljen del programskega okolja Siemens Totally Integrated Automation Portal (TIA Portal), ki uporabnikom omogoča nastavljanje pogonskega sklopa. V okviru okolja TIA Portal so predstavljeni postopki za izvedbo vodenja z metodo U/f in za izvedbo vektorskega vodenja, pri čemer je poudarek na avtomatizirani nastavitvi parametrov pretvornika. Predstavljeni rezultati eksperimentalne analize zajemajo primerjavo med odzivi pogonskega sklopa v primeru različnih načinov vodenja, ki jih pretvornik omogoča. Na koncu so podani še napotki za ročno prilagoditev parametrov regulatorja hitrosti za doseganje želene dinamike pogona v primeru vektorskega vodenja.
Ključne besede: Asinhronski stroj, Siemens Totally Integrated Automation Portal, SINAMICS G120, vektorsko vodenje, vodenje U/f.
Objavljeno v DKUM: 13.10.2023; Ogledov: 382; Prenosov: 85
.pdf Celotno besedilo (4,86 MB)

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