Article
Mathematics, Applied
Yanlai Chen, Lijie Ji, Akil Narayan, Zhenli Xu
Summary: The paper introduces a new solution called Reduced Over-Collocation method (ROC), which extends the EIM method as a direct solver for efficiently solving nonlinear pPDE problems. The method demonstrates high efficiency and stability in both offline and online stages.
JOURNAL OF SCIENTIFIC COMPUTING
(2021)
Article
Engineering, Electrical & Electronic
Ravi Mutukutti, Jose Marti
Summary: This paper introduces an EMTP-H model for water dynamics based on the analogy between hydraulic equations and EMTP transmission line equations. The proposed model accurately describes the dynamics of shaft torque due to the propagation of water from the reservoir to the turbine, and avoids the frequency oscillation errors caused by simplified modelling.
ELECTRIC POWER SYSTEMS RESEARCH
(2022)
Article
Engineering, Electrical & Electronic
Marius Langwasser, Giovanni De Carne, Marco Liserre, Matthias Biskoping
Summary: HVDC can provide frequency regulation during disturbances by controlling power flow between AC areas, but this may lead to power imbalance and endanger system stability. This work proposes HVDC primary frequency regulation controlling voltage-dependent loads to cope with power variation in affected areas using energy from healthy area loads. The method is evaluated analytically and verified through simulations and tests on a large IEEE 39 bus system.
IEEE TRANSACTIONS ON POWER DELIVERY
(2021)
Article
Engineering, Electrical & Electronic
Felipe Luis Probst, Mauricio Valencia Ferreira da Luz, Stefan Tenbohlen
Summary: This paper presents the implementation of a nonlinear model of a Capacitive Voltage Transformer (CVT) to evaluate the transient response in conformity with the international standard IEC 61869-5. The work is divided into three main steps: electrical tests to measure the CVT parameters and frequency response; implementation of linear mathematical modeling and an optimization algorithm to estimate unmeasured parameters; and implementation of nonlinear modeling in a simulation program for electromagnetic transients. The model is reliable and can be used for the simulation of ferroresonance and transient response tests following the IEC 61869-5 when no laboratory structure is available.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
Article
Mechanics
A. Viudez
Summary: Exact solutions of the time-dependent three-dimensional nonlinear vorticity equation for Euler flows with spherical geometry are provided. The velocity solution is the sum of a multipolar oscillatory function and a rigid cylindrical motion with swirl. These solutions are important for understanding inertial oscillations and nonlinear effects in multipolar flows.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Electrical & Electronic
Lihao Wu, Bo Zhang, Yanwei Jiang
Summary: In this article, a novel parity-time (PT)-symmetric wireless power transfer (WPT) system with reduced switching frequency and improved step-down conversion ratio is proposed by combining the phase synchronization method (PSM) and high harmonic operation (HHO). The power transferred to the receiver side is carried by the nth harmonic. It is demonstrated that constant current (CC) and constant voltage (CV) independent of coupling coefficient and load resistance can be obtained without wireless communication and additional dc-dc converters. A prototype with a 6-A charging current and a 36-V charging voltage is built to verify the feasibility of the proposed method.
IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION
(2023)
Article
Environmental Sciences
Yan Zhao, Lixin Zhang, Xin Zhao, Jin Liu, Ming Gao
Summary: High-frequency electronic descaling devices use high-frequency electromagnetic fields to slow down scale growth by changing the morphology of scaling substances and the physicochemical properties of water. Simulation results show that square wave excitation generates greater magnetic field energy compared to sine wave excitation, and increasing voltage leads to a continuous rise in the peak value of magnetic field energy. Increasing frequency causes a slight decrease in the peak values of magnetic field energy and magnetic flux within a certain range, followed by a rapid decrease due to waveform relaxation. Time and frequency increases significantly increase the influence of relaxation time.
Article
Engineering, Electrical & Electronic
Dong Wang, Mengqian Hou, Yifei Guo
Summary: This paper proposes a novel off-line TW fault location principle for transposed HVAC transmission lines to address the robustness against uncertain factors. By analyzing the frequency-dependent characteristic of HVAC transmission lines, a novel TW fault location principle is proposed, which consists of arrival time detection of TW and accurate frequency calculation of TW.
IEEE TRANSACTIONS ON POWER DELIVERY
(2021)
Article
Mechanics
Alexis Gomel, Corentin Montessuit, Andrea Armaroli, Debbie Eeltink, Amin Chabchoub, Jerome Kasparian, Maura Brunetti
Summary: The evaluation and consideration of mean flow in wave evolution equations have significant implications in various domains, such as pollutant transport in the ocean and energy and momentum exchanges between waves and ocean circulation. We have derived an accurate expression of mean flow in finite water depth, which accurately corresponds to the deep-water limit at third order in steepness and resembles second-order formulations in intermediate water. Additionally, we have provided envelope evolution equations at fourth order in steepness for the propagation of unidirectional wave groups, including the mean flow term, which is crucial for accurately modeling water wave flume experiments in arbitrary depths.
Article
Physics, Multidisciplinary
E. Polini
Summary: Quantum noise is limiting the sensitivity of ground-based gravitational wave detectors at both high and low frequencies. By implementing frequency-dependent squeezing, improvements in sensitivity have been demonstrated, although challenges remain in terms of interfacing and coupling with the interferometer. Additional measures, such as installing baffles to limit stray light, are being taken to mitigate such issues.
Article
Computer Science, Information Systems
Youpeng Huangfu, Luca Di Rienzo, Shuli Yin
Summary: This paper presents an improved multi-conductor transmission line (MTL) model to better predict the electromagnetic interference (EMI) performance of interconnects and cables. The model incorporates partial resistance and inductance parameters, and demonstrates how to describe the frequency dependent behavior of these parameters in time domain simulations. Additionally, an equivalent node-to-node admittance functions (NAFs) implementation is carried out and numerically validated for its correctness and effectiveness in time domain analysis.
Article
Automation & Control Systems
Manje Yea, Jingook Kim, Ki Jin Han
Summary: This work presents a frequency-dependent bearing voltage model for squirrel-cage induction motors. The study analyzes the behavior of bearing voltage ratio (BVR) at different frequencies and proposes an equivalent circuit based on the BVR characteristic. The proposed model is verified and parametric studies are conducted to examine the effects of motor system parameters on bearing voltage.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Mathematics, Applied
Huaijun Yang
Summary: This paper investigates the superconvergent properties of time-dependent Stokes equations. By utilizing a new approach and the special characteristics of the finite element space pair on a rectangular mesh, superclose error estimations for velocity and pressure in different norms are obtained, and corresponding superconvergence results are derived using a suitable postprocessing approach.
APPLIED NUMERICAL MATHEMATICS
(2022)
Article
Chemistry, Multidisciplinary
Hugo Merbouche, Isabella Boventer, Victor Haspot, Stephane Fusil, Vincent Garcia, Diane Gouere, Cecile Carretero, Aymeric Vecchiola, Romain Lebrun, Paolo Bortolotti, Laurent Vila, Manuel Bibes, Agnes Barthelemy, Abdelmadjid Anane
Summary: Multiferroics combined with ferromagnets in fully epitaxial heterostructures achieve voltage-controlled and reconfigurable magnonic systems, showing potential for significant impact in the field of magnonics and eventual large-scale integration of magnonic devices.
Article
Automation & Control Systems
Yiming Zhang, Zhiwei Shen, Wenbin Pan, Hui Wang, Yuanchao Wu, Xingkui Mao
Summary: This paper proposes a reconfigurable topology based on a three-coil structure to achieve constant current (CC) and constant voltage (CV) charging. The system has the advantages of simplicity and low cost.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2023)
