Article
Computer Science, Information Systems
Jan Barta, Ladislav Knebl, Gerd Bramerdorfer, Iveta Lolova, Siegfried Silber, Ondrej Vitek
Summary: This paper utilizes topology optimization to find the optimal rotor bar design for a line-start permanent magnet synchronous machine, improving its performance compared to traditional induction machines.
Article
Automation & Control Systems
Daniel Arnstrom, Daniel Axehill
Summary: In model-predictive control, it is important to efficiently solve optimization problems and have upper bounds on worst-case solution time. We propose an algorithm to compute the sequence of subproblems that an active-set algorithm solves and set worst-case bounds on iteration count and solution time. The usefulness of our method is illustrated on a set of quadratic program problems.
IEEE TRANSACTIONS ON AUTOMATIC CONTROL
(2022)
Article
Automation & Control Systems
Qianwen Duan, Wei Tian, Qifan Yang, Xiaonan Gao, Yao Mao, Petros Karamanakos, Ralph Kennel, Marcelo Lobo Heldwein
Summary: This article presents two computationally efficient methods for selecting the optimal modulated voltage that can achieve superior dynamic performance for surface-mounted permanent magnet synchronous motors (SPMSMs). The first method is a simple overmodulation method based on common-mode-saturation injection (CMSI), which has very low computational cost and can easily find the voltage vector on the boundary. The second method is a quadratic program (QP) based deadbeat (DB) control, which formulates the control problem as a constrained QP and solves it with an efficient solver based on an active-set method. Simulative and experimental investigations are conducted to demonstrate the effectiveness of both methods for an SPMSM.
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
(2023)
Article
Engineering, Electrical & Electronic
Vahid Zamani Faradonbeh, Akbar Rahideh
Summary: A fast hybrid analytical model is proposed to predict the on-load performance of double-layer IPMSMs considering iron bridges saturation and slotting effects. The model utilizes constant flux in the magnetic equivalent circuit method for iron bridges saturation and flux path function and VSCs for slotting effects in 1-D and 2-D analytical methods.
IET ELECTRIC POWER APPLICATIONS
(2022)
Article
Operations Research & Management Science
Na Huang
Summary: The gradient method is a simple optimization approach that relies on the choice of stepsize for efficiency. This paper analyzes a class of gradient methods with a specific stepsize property in the context of minimizing strictly convex quadratic functions, establishing R-linear convergence and estimating the R-factor. If the stepsize can be expressed in terms of Rayleigh quotients of the inverse Hessian matrix, these methods converge R-linearly with R-factors bounded above by 1 - 1 1/x, where x is the associated condition number.
COMPUTATIONAL OPTIMIZATION AND APPLICATIONS
(2022)
Article
Mathematics, Applied
F. I. L. I. P. P. O. Zanetti, J. A. C. E. K. Gondzio
Summary: This paper introduces an interior point method that relies on an inner termination criterion and derives new indicators for early termination of the inner iterations. The method has been tested on quadratic optimization problems and compared to standard residual tests, showing significant improvements in terms of inner iterations and solution time savings.
SIAM JOURNAL ON SCIENTIFIC COMPUTING
(2023)
Article
Mechanics
Stefan Hartung, Ingo Rehberg
Summary: The experimental study investigated the coupling of two rotating spherical magnets, finding a cogging-free coupling at specific angles where the driven magnet is phase-locked to the driving one with reversed rotation. For other angles, a more complex dynamical behavior was observed, divided into three different classes based on deviation from periodic motion and total harmonic distortion of the rotation of the driven magnet. The experimental results were explained by a mathematical model with dipole-dipole interaction and friction terms.
ARCHIVE OF APPLIED MECHANICS
(2021)
Article
Engineering, Electrical & Electronic
H. Bulent Ertan, Ilker Sahin
Summary: This study evaluates different inductance measurement methods for different types of motors, and measures the d-axis and q-axis inductances of two surface-mount PM motors at standstill and under running conditions. The dependence of inductances on current magnitude, frequency, and excitation signal waveform is investigated. A new inductance measurement method is introduced for running tests. The results from different standstill tests and running tests are compared and evaluated.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Computer Science, Information Systems
Eghbal Hosseini, Line Reinhardt, Danda B. Rawat
Summary: This article discusses two gradient-based methodologies for solving LP and NLP problems and their efficiency in solving optimization problems with large feasible spaces.
IEEE INTERNET OF THINGS JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Sarit Khirirat, Sindri Magnusson, Mikael Johansson
Summary: The paper discusses the shift in optimization algorithm operating regime in the era of big data and introduces the improvement in solution accuracy through compression error compensation. Through experiments, it shows the advantages of Hessian-aided error compensation in quadratic problems and the strong convergence guarantees for stochastic gradient descent.
IEEE TRANSACTIONS ON SIGNAL PROCESSING
(2021)
Article
Engineering, Electrical & Electronic
Dong-Ho Kim, Hyun-Jo Pyo, Won-Ho Kim, Ju Lee, Ki-Doek Lee
Summary: This study proposes a spoke-type PMSG rotor shape design for low capacity wind turbines that considers magnetization and cogging torques. The rotor shape with improved magnetization performance is designed by analyzing the principle of magnetization and the factors influencing magnetization performance. An asymmetric rotor barrier structure is applied to reduce the cogging torque, and the performance of the final model is analyzed using finite element analysis. The temperature saturation during the operation of the final model is analyzed using a thermal network method, and the irreversible demagnetization is validated.
Article
Engineering, Chemical
Ji-Chang Son, Kyung-Pyo Yi, Dong-Kuk Lim
Summary: The internal division point genetic algorithm (IDP-GA) proposed in this paper aims to lessen the computational burden of multi-variable multi-objective optimization problems, such as optimal design of electric bicycles, using finite element analysis. The algorithm considers various objectives and reduces the number of function calls with novel strategies, demonstrating superiority over conventional optimization methods. The applicability of IDP-GA in practical electric machine design was verified by successfully improving the design of an electric bicycle propulsion motor.
Article
Chemistry, Multidisciplinary
Whei-Min Lin, Chung-Yuen Yang, Ming-Tang Tsai, Yun-Hai Wang
Summary: This study proposes a method combining DPSO and SQP for solving unit commitment problems for ancillary services, with effective results demonstrated using real data. The research shows that costs with ancillary services are lower than those without ancillary services.
APPLIED SCIENCES-BASEL
(2021)
Article
Mechanics
Liaoyuan Ran, Dunant Halim, Chung Ket Thein, Michael Galea, Weiduo Zhao
Summary: This study presents a systematic rotor structural sizing optimization method that incorporates semi-analytical and numerical modeling, taking into account multiple mechanical design parameters. It provides an effective design optimization procedure for high-speed electrical machines, optimizing power density and dynamics stability during operation.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Engineering, Electrical & Electronic
Wenjuan Zhang, Litao Dai, Zhiman Xiang, Qiuwei Wu, Sheng Huang, Jian Gao
Summary: This paper proposes a new design optimization method for permanent magnet synchronous generators in hydropower plants to improve the combined operating efficiency. By studying hydrological data and turbine operating trajectory, an efficiency analysis model is developed under different hydrological conditions and solved by an improved genetic algorithm. Simulation and experimental tests verify the improvement in annual cycle efficiency under different load conditions.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2021)
Article
Engineering, Multidisciplinary
Armin Galetzka, Dimitrios Loukrezis, Herbert De Gersem
Summary: This study proposes a data-driven magnetostatic finite-element solver that can handle strongly nonlinear material responses, utilizing heterogeneous weighting factors to locally balance the objective function and address unbalanced measurement data sets. Numerical experiments demonstrate significant improvements in solution accuracy and solver efficiency with this modification.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2021)
Article
Engineering, Multidisciplinary
Tristan Gally, Peter Groche, Florian Hoppe, Anja Kuttich, Alexander Matei, Marc E. Pfetsch, Martin Rakowitsch, Stefan Ulbrich
Summary: In engineering applications, models are used to describe processes, particularly in forming machines. This paper proposes a method to identify model uncertainty using parameter identification, optimal design of experiments, and hypothesis testing. By optimizing sensor positions, specific model parameters can be determined and confidence regions can be computed.
OPTIMIZATION AND ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Armin Galetzka, Dimitrios Loukrezis, Herbert De Gersem
Summary: This paper demonstrates the practical usability of data-driven solvers in computationally demanding three-dimensional problems by directly utilizing real-world measurement data. The results indicate that the data-driven solver can recover conventional solutions and show good flexibility and applicability in practical usage.
COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Yvonne Spaeck-Leigsnering, Maren Greta Ruppert, Erion Gjonaj, Herbert De Gersem, Volker Hinrichsen
Summary: This paper investigates the thermal stability of station class surge arresters and proposes methods for improving heat transfer and predicting thermal stability, reducing the need for laboratory tests.
IEEE TRANSACTIONS ON POWER DELIVERY
(2022)
Article
Engineering, Multidisciplinary
Ketson R. M. dos Santos, Dimitris G. Giovanis, Katiana Kontolati, Dimitrios Loukrezis, Michael D. Shields
Summary: A novel surrogate model based on Grassmannian diffusion maps and geometric harmonics is developed for predicting the response of complex physical phenomena. The model utilizes low-dimensional representation and mapping techniques to reconstruct the full solution. The performance of the model is verified through various examples.
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
(2022)
Article
Mathematics, Interdisciplinary Applications
Stefan Kurz, Herbert De Gersem, Armin Galetzka, Andreas Klaedtke, Melvin Liebsch, Dimitrios Loukrezis, Stephan Russenschuck, Manuel Schmidt
Summary: The integration of machine learning and artificial intelligence technologies with physical modeling based on first principles will have a fundamental impact on scientific computing in engineering. This paper provides background information, discusses trends, and showcases recent achievements from an applied mathematics and industrial perspective. Examples include characterizing superconducting accelerator magnets, data-driven magnetostatic field simulation, and Bayesian free-shape optimization on a printed circuit board.
JOURNAL OF MATHEMATICS IN INDUSTRY
(2022)
Article
Engineering, Electrical & Electronic
Jonathan Stysch, Andreas Klaedtke, Herbert De Gersem
Summary: The article introduces a broadband extraction technique using the finite-element method for parasitic extraction, showing how a state-of-the-art stabilization approach based on a split of the Sobolev space is applied to address the low- to high-frequency regime issue.
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
(2022)
Article
Operations Research & Management Science
Elisabeth Diehl, Johannes Haubner, Michael Ulbrich, Stefan Ulbrich
Summary: In this paper, optimal control problems for two-phase Navier-Stokes equations with surface tension are analyzed. By utilizing the L-p-maximal regularity of the linear problem and recent well-posedness results for small data, the differentiability of the solution with respect to controls is demonstrated. The study incorporates formulations transforming the interface to a hyperplane, deducing differentiability results in physical coordinates, and deriving sensitivity equations of a Volume-of-Fluid type formulation.
COMPUTATIONAL OPTIMIZATION AND APPLICATIONS
(2022)
Article
Engineering, Multidisciplinary
Ion Gabriel Ion, Dimitrios Loukrezis, Herbert De Gersem
Summary: This work presents a numerical solver combining isogeometric analysis (IGA) and tensor train (TT) decomposition for approximating parameter-dependent PDEs on geometries. The proposed method effectively handles parameter dependencies and demonstrates high computational efficiency and compression ratios.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Engineering, Electrical & Electronic
Laura A. M. D'Angelo, Yvonne Spack-Leigsnering, Herbert De Gersem
Summary: This work proposes a hybrid numerical method to tackle the multi-scale problem in the quench simulation of superconducting accelerator magnets.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Engineering, Electrical & Electronic
Vefa Karakasl, Fabian Gross, Tristan Braun, Herbert De Gersem, Gerd Griepentrog
Summary: In this article, a high-frequency six-port three-phase induction motor model is proposed. The model utilizes multistage RLC circuits to accurately predict impedance. It is derived from CM and DM equivalent circuits and takes into account the nonlinear inductance effect in the low-frequency range. Additionally, the model can be easily transformed between delta and star configurations.
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY
(2022)
Article
Engineering, Electrical & Electronic
Jonathan Stysch, Andreas Klaedtke, Herbert de Gersem
Summary: This study proposes a stable and efficient method for extracting frequency-dependent parasitic effects of computer-aided design models. By using the finite element method, an equivalent circuit is generated by combining the results of full-wave simulation and magnetoquasistatic simulation, along with capacitances computed in an electrostatic simulation. This method ensures stability by separating resistive and inductive effects and avoiding ill-conditioned impedance or scattering matrices at low frequencies.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Engineering, Electrical & Electronic
Erik Schnaubelt, Herbert De Gersem, Nicolas Marsic
Summary: This paper introduces a method for calculating electromagnetic wave problems using axial symmetry, which reduces computational complexity but introduces new difficulties. By combining finite element formulations with perfectly matched layers, open problems can be addressed. A comparison and discussion of different combinations of axial symmetric FE formulations and PMLs are presented, using a dielectric sphere in open space as a test case. A superconducting Fabry-Perot photon trap is also considered as an application example.
INTERNATIONAL JOURNAL OF NUMERICAL MODELLING-ELECTRONIC NETWORKS DEVICES AND FIELDS
(2023)
Article
Engineering, Mechanical
S. Puchtler, T. Schirra, E. Kirchner, Y. Spaeck-Leigsnering, H. De Gersem
Summary: This study compares different methods for calculating the capacitance of unloaded rolling elements to improve the electric characterization of rolling element bearings. Semi-analytical approximations and finite element simulations are used, and a closed-form analytical two-dimensional solution is derived for comparison. The results show that the most common semi-analytical approximation, which uses effective radii to express the contact geometry, reproduces the trend from numerical and analytical calculations, but overestimates the results derived from numerical simulations. Another semi-analytical approach is presented that delivers better results for the capacitance of unloaded point contacts.
TRIBOLOGY INTERNATIONAL
(2022)
