Technische Hochschule Würzburg-Schweinfurt Publikationsserver OPUS
Not a member yet
5300 research outputs found
Sort by
Powder Bed Monitoring Using Semantic Image Segmentation to Detect Failures during 3D Metal Printing
No full textMonitoring the metal Additive Manufacturing (AM) process is an important task within the scope of quality assurance. This article presents a method to gain insights into process quality by comparing the actual and target layers. Images of the powder bed were captured and segmented using an Xception–style neural network to predict the powder and part areas. The segmentation result of every layer is compared to the reference layer regarding the area, centroids, and normalized area difference of each part. To evaluate the method, a print job with three parts was chosen where one of them broke off and another one had thermal deformations. The calculated metrics are useful for detecting if a part is damaged or for identifying thermal distortions. The method introduced by this work can be used to monitor the metal AM process for quality assurance. Due to the limited camera resolutions and inconsistent lighting conditions, the approach has some limitations, which are discussed at the end
Lehrlabor³ - ein Netzwerk zur teambasierten Lehrentwicklung: Einblicke und Ergebnisse in ein hochschul-und rollenübergreifendes Programm zur Lehrentwicklung in der Hochschulbildung 05/2022–04/2023
No full text
Quarterly on Refugee Problems (2, 4)
Get PDFThis issue of the QRP mainly summarizes contributions, discussions, findings and conclusions from the 68th International Conference of the Association for the World Refugee Problem (AWR) on the subject of “Safe, Orderly and Regular Migration: Transnational Skill Partnerships”. It was held at the Technical University of Applied Sciences Würzburg-Schweinfurt on 24-26 May 2023 and gathered expertise from science and practice, from receiving and sending States. Additionally it looks at the financial inclusion of forcibly displaced persons and comments on the legal fate of the Palestinian refugees in the light of the current war in the Gaza Strip
Werte fundieren, Werteorientierte Argumentation, Founders for Future (engl./dt.), Sustainable Finance implementieren, Module zu Impact Entrepreneurship, Nachhaltigkeit & Wertemanagement, Virtuelle Hochschule Bayern – smartVHB
No full textHybrid Phasor- and EMT-based Multi-Terminal MMC-HVDC Model with Grid-Forming Control
No full textThe objective of this paper is to apply a hybrid phasor-(RMS) and electromagnetic transient-based (EMT) simulation approach to a multi-terminal modular multilevel converter high voltage direct current (MT MMC-HVDC) model. The MMC of the MT-HVDC are implemented with grid-following and grid-forming control. An overview of the MT MMC-HVDC is given and the grid-forming and voltage droop control are described. The AC and DC networks of the MMC are divided into an RMS and an EMT partition with different simulation time steps. The grid-forming and grid-following control with inner AC current control are assigned to the RMS partition. The total energy and inner converter control are assigned to the EMT partition. The model is initialized for a correct transition from power flow to time domain simulation. The approach is implemented in a meshed power system model, where grid-forming MMC provide voltage and frequency for an offshore wind farm and a synchronous grid. The simulations are performed with the AC networks in RMS and the DC networks in EMT. The results show that the interactions between the AC and DC grids can be studied in a hybrid simulation framework. The DC system response is detailed, while the AC system is reduced to machine and controller dynamics
PyEMMO - a Python based software for the finite element modelling of electrical machines in ONELAB
Get PDFMulti-objective optimizations are almost essential in the design process of electrical machines due to constantly increasing requirements for efficiency and power density. In this context, open-source simulation software offers the possibility to parallelize calculations free of license costs and thus to achieve a reduced calculation time. This paper presents the software project PyEMMO (Python Electrical Machine Modeling in ONELAB) for the finite element simulation of electrical machines in the open source program ONELAB. The object-oriented program structure and the objectives of the project are the main focus. Furthermore, the latest features are discussed, which include the geometry definition via a toolbox system, the simulation data interface based on the JSON file format and the calculation of iron losses.Multizieloptimierungen sind im Designprozess elektrischer Maschinen aufgrund stetig steigender Anforderungen an Wirkungsgrad und Leistungsdichte nahezu unabdingbar. Dabei bietet Open-Source Simulationssoftware die Möglichkeit lizenzkostenfrei Berechnungen zu parallelisieren und somit eine reduzierte Berechnungszeit zu erreichen. Dieser Beitrag stellt das hierfür initiierte Softwareprojekt PyEMMO (Python Electrical Machine Modeling in ONELAB) für die Finite-Elemente-Simulation elektrischer Maschinen im Open-Source-Programm ONELAB vor. Die objektorientierte Programmstruktur und die Ziele des Projekts stehen hierbei im Vordergrund. Des Weiteren wird auf den aktuellen Funktionsumfang eingegangen, welcher unter anderem die Geometriedefinition über ein Baukastensystem, das Simulationsdateninterface basierend auf dem JSON-Dateiformat und die Berechnung der Eisenverluste beinhaltet
An FEM simulation model of oil-pressboard insulating systems for HVDC transformers
No full textIn this contribution, a simulation model for the description of the nonlinear dielectric behaviour of an insulation system composed of mineral oil and oil-impregnated pressboard is presented. The model was verified by comparing the simulation results with electric field and current measurements. At the outset, the ideal case, where a homogeneous initial charge carrier distribution according to the definition of ohmic conductivity is present, is analysed to establish the preliminary foundations pertaining to a typical measurement. Following that, the influence of distinct charge carriers on the measured quantities are investigated by altering their parametrisations. In contrast to the ideal case, a real measurement reveals a current trend, that can be explained by an excess amount of initial charge carriers related to the oil-impregnated pressboard layers. Potential possibilities to the origin of the surplus are discussed. Furthermore, it is shown that the dissociable and intrinsic charge carriers alone can reconstruct the measured quantities in terms of the transient behaviour. This points out that, for the field strength studied here ( E ≤ 1 kV/mm ), the charging of the highly resistive pressboard barriers is dominated by the dissociation of charge carriers in the oil gaps