Results 241 to 250 of about 10,921,507 (275)
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On the Spectrum of Ultralow-Frequency Oscillations of the Ionosphere in the Pc1 Range
Izvestiya, Physics of the Solid Earth, 2023The idea of Alfvén waves plays a key role in the theory of ultra-low-frequency (ULF) electromagnetic oscillations of cosmic origin. The article is dedicated to the 80th anniversary of the discovery of Alfvén waves. It focuses on the Ionospheric Alfvén Resonator, or IAR for short. ULF oscillations are excited in the IAR in the Pc1 range (0.2–5 Hz). When
Anatol Guglielmi +2 more
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Ultra-Low-Frequency, Three-Phase Oscillator
Proceedings of the IRE, 1954This paper describes the design of a three-phase oscillator covering the range from 0.01 to 1,000 cycles per second. The problems peculiar to this frequency range, and their solutions, are discussed. Certain advantages inherent in three-phase operation are explained.
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Ultra Low Power Low Frequency On-chip Oscillator for Elapsed Time Counter
2019 32nd International Conference on VLSI Design and 2019 18th International Conference on Embedded Systems (VLSID), 2019This paper presents a design of CMOS current starved inverter based oscillator which is used to drive the counters that act as a component in the elapsed time counter. A low power temperature independent biasing circuit is designed to enhance the performance meeting the frequency variations.
Sachin Kalburgi +8 more
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Analysis of the Influence of System Characteristics on Ultra-Low Frequency Oscillation
2019The ultra-low frequency oscillation phenomenon is not only related to the characteristics of the governor of the hydropower unit, but also closely related to the system characteristics. Based on the detailed analysis of the hydroelectric governor model, a simplified analysis model of the ultra-low frequency oscillation of the power grid is proposed ...
Xuelian Wu +3 more
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Ultra low frequency CMOS ring oscillator design
2014 Recent Advances in Engineering and Computational Sciences (RAECS), 2014In this paper, the concept of CMOS thyristor has been used to implement low frequency ring oscillator using 2.5 volt power-supply and 1pF load capacitance using 250nm technology. By using the conventional CMOS thyristor structure the frequency of the output sinusoidal waveform is of the order of KHz, which has been further improved in proposed CMOS ...
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Eigen Ultra-Low-Frequency Magnetosonic Oscillations of the Near Plasma Sheet
Cosmic Research, 2008A critical analysis of existing theories of the magnetospheric resonator for fast magnetosonic waves is performed. A new variant of the theory is suggested, according to which the near-Earth part of the plasma sheet plays the role of the resonator. It is shown that the magnetosonic wave is locked inside this region over its entire boundaries. The eigen
A. S. Leonovich, V. A. Mazur
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Emergency Control Strategy of Ultra-low Frequency Oscillations Based on WAMS
2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia), 2019In this paper, an emergency control strategy of ultra-low frequency oscillations (ULFO) is presented. The multi-signal Prony algorithm is used to identify frequency signals from WAMS. Then the criterion of ULFO is proposed based on the Prony analysis results.
Qin LIU +7 more
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Mode Identification and Damping Torque Analysis of Ultra-Low Frequency Oscillations
2019 IEEE Sustainable Power and Energy Conference (iSPEC), 2019After the asynchronous interconnection of Yunnan and South China Power Grid, a long period of ultra-low frequency oscillation occurred, which seriously affected the safe and stable operation of the system. This paper presents the damping analysis of hydraulic turbine governing systems under ultra-low frequency oscillations.
Junfeng Zhang +4 more
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Analysis of ultra-low frequency oscillation in yunnan asynchronous sending system
2017 IEEE Power & Energy Society General Meeting, 2017Yunnan power grid has a large-scale hydropower station whereby the power generated at the station is been transmitted via high-voltage direct current (HVDC) transmission lines under asynchronous operation mode. In the system performance test of Yunnan asynchronous operation, 0.05 Hz ultra-low frequency oscillation occurred in the grid.
Yiping Chen +6 more
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Ultra Low-Frequency Oscillations of a Solar Filament Observed by the GONG Network
Solar Physics, 2016The data of ground-based telescopes of the Global Oscillation Network Group (GONG) obtained in the $\mathrm{H}\upalpha$ line provide an opportunity to study the long-period oscillations of chromospheric ...
V. I. Efremov +2 more
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