Results 51 to 60 of about 48,127 (315)

Impact of high-frequency harmonics (0–9 kHz) generated by grid-connected inverters on distribution transformers [PDF]

, 2020
The level of current harmonics circulating in a transformer winding can affect its operating temperature and lifetime. Although the existing standards mainly consider the impact of harmonics up to 2 kHz, higher frequency harmonics generated by high power
Eghbal, Daniel, Martin, Daniel, Yaghoobi, Jalil, Zare, Firuz, Memisevic, Rizah, Alduraibi, Abdulrahman   +5 more
core   +1 more source

High Frequency Harmonics Emission in Smart Grids [PDF]

, 2013
The term ‘smart grid‘, is nowadays very often used in many publications and so far has not been explicitly defined, however it refers mainly to such an operation of electricity delivery process that allows to optimize energy efficiency by flexible interconnection of central and distributed generators through transmission and distribution system to ...
openaire   +1 more source

Air‐Pressure–Actuated Vibroacoustic Metamaterial With Tunable Bandgap: Design, Modeling, and Characterization

Advanced Engineering Materials, EarlyView.
This article presents the design, modeling, and characterization of air‐pressure–actuated programmable vibroacoustic metamaterials (PVAMM). The study focuses on leveraging air pressure to dynamically tune resonance frequencies for effective noise attenuation.
William Kaal, Michael M. Becker, Sarah C. L. Fischer   +2 more
wiley   +1 more source

Sensorless position control of permanent magnet motors with pulsating current injection and compensation of motor end-effects [PDF]

, 2011
The sensorless position control of permanent-magnet motors is successfully implemented by superimposing a high-frequency voltage signal on the voltage reference or adding a high-frequency current signal to the current reference.
G Pellegrino, CUPERTINO, Francesco, Pellegrino G, Cupertino, F., SALVATORE L., Pellegrino, Gian-Mario Luigi, CUPERTINO F, Giangrande, P., P Giangrande, Salvatore, L., GIANGRANDE P, L Salvatore, PELLEGRINO, GIAN - MARIO LUIGI, F Cupertino   +13 more
core   +1 more source

LCCR Filter Design Method and High‑Frequency Current Harmonic Suppression in PMSM

Nanjing Hangkong Hangtian Daxue Xuebao
The switching current harmonics caused by pulse width modulation（PWM） leads to overheating of the drive motor in vacuum environment， which affecting the reliability of the molecular pump.
WANG Tianzuo, ZHOU Yang, ZHANG Hanlin, ZHOU Jin   +3 more
doaj   +1 more source

Magnitude-Reshaping Strategy for Harmonic Suppression of VSG-Based Inverter Under Weak Grid

IEEE Access, 2020
Driven by inertial demand from the grid, the virtual synchronous generators (VSGs) are widely utilized in distributed generation systems. However, harmonic sources in the distributed generation systems with high grid impedance will cause grid voltage ...
Wen Yang, Mingyu Wang, Saddam Aziz, Ali Yousaf Kharal   +3 more
doaj   +1 more source

High-frequency vector harmonic mode locking driven by acoustic resonances [PDF]

Optics Letters, 2019
A controllable passive harmonic mode locking (HML) in an erbium-doped fiber laser with a soliton pulse shaping using a single-wall carbon nanotube has been experimentally demonstrated. By increasing the pump power and adjusting the in-cavity polarization controller, we reached the 51st-order harmonic (902 MHz) having the output power of 37 mW.
KBASHI, H, Sergeyev, Sergey, AL-ARAIMI, M, ROZHIN, A., Korobko, D.A., Fotiadi, Andrei   +5 more
openaire   +3 more sources

Is an Apple an Orange? A Large Language Model Benchmark for Candidate Term Extraction and Subclass Decisions Against Upper Ontologies in Engineering and Materials Science

Advanced Engineering Materials, EarlyView.
Building machine‐readable vocabularies for materials science is slow, expert‐driven work. This study benchmarks 13 large language models on two of its first steps: finding candidate terms in engineering articles and deciding where they belong in a class hierarchy.
Thomas Bjarsch, Maximilian Holland, Klaus Drechsler, Johannes Schilp   +3 more
wiley   +1 more source

An interferometer experiment to explore the aspect angle dependence of stimulated electromagnetic emission spectra [PDF]

, 2005
International audienceWhen the Earth's ionosphere is irradiated by a radiofrequency (RF) electromagnetic wave of sufficiently high power density and tuned to match a natural E- or F-region plasma frequency, ionospheric magnetoionic wave modes may be ...
Khudukon, B. Z., Rietveld, Michael T., Yurik, R.Yu, Brekke, A., Belyey, Tereshchenko, Tereshchenko, E., Khudukon, B., Rietveld, M., Hoz, C. La, Belyey, Vasyl, Tereshchenko, E.D., Hagfors, Yurik, R. Yu., Khudukon, Yu. Yurik, Heinselman, C., Grill, Brekke, Belyey, V., Isham, B., Rietveld, Hagfors, T., Heinselman, Brekke, Asgeir, Rietveld, M. T., La Hoz, C., Isham, null La Hoz, Grill, M., Yurik, Yu., null null, Yurik, R. Yu., Yurik, R., La Hoz, Cesar, Tereshchenko, E. D., La Hoz   +36 more
core   +1 more source

High Frequency Harmonic Cancellation in Ball-screw Drives

Procedia CIRP, 2012
AbstractIn many machining processes cutting forces are of harmonic nature. The frequency content of these forces may extend far beyond the closed-loop bandwidth of the commonly used feed drive controllers. In ball screw drives, high–frequency disturbances may also originate from repetitive errors synchronized with the rotation of the ball screw.
Hosseinkhani, Yasin, Erkorkmaz, Kaan
openaire   +1 more source