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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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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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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 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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Ultra low-power, -area and -frequency CMOS thyristor based oscillator for autonomous microsystems
2015 Nordic Circuits and Systems Conference (NORCAS): NORCHIP & International Symposium on System-on-Chip (SoC), 2015In this paper we present a minimal sized CMOS thyristor based oscillator, which is able to provide a clock signal of $$\approx$$ź20 Hz. The oscillator was designed as a timer or clock generator for autonomous microsystem applications. The chip area of the oscillator is 18 µm by 35 µm and it is able to run for more than 10 min when supplied from a 10 nF
Dominic A. Funke +6 more
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An ultra-low frequency ring oscillator with programmable tracking using a phase-locked loop
2012 IEEE 55th International Midwest Symposium on Circuits and Systems (MWSCAS), 2012This paper presents a programmable ultra-low frequency ring oscillator designed in a 0.5µm CMOS technology with 3.3 V power supply. In normal operation, the oscillator produces a periodic signal without external inputs (other than power and ground).
Tsung-Hsueh Lee, Pamela Abshire
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Low-frequency noise properties of SiGe HBT's and application to ultra-low phase-noise oscillators
IEEE Transactions on Microwave Theory and Techniques, 1998This paper presents an extensive electrical characterization of Si/SiGe/Si heterojunction bipolar transistors (HBT's) grown by molecular beam epitaxy (MBE). These devices are designed for microwave and millimeter-wave applications since they present a maximum oscillation frequency in the 40-GHz range. The processing technology, featuring a high-quality
B. Van Haaren +7 more
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Suppression Strategy of Ultra-Low Frequency Oscillation in Yunnan Power Grid with BESS
2019 North American Power Symposium (NAPS), 2019Many problems related to power system frequency have occurred in Yunnan Province ─a province in southwestern China with high proportion of hydro-turbine generators. Yunnan Power Grid is a typical direct-current (DC) sending grid and the installed capacity of hydro-generators has accounted for more than 70% of the total capacity after asynchronous ...
Yixuan Chen +5 more
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Ultra-low power frequency synthesizer based on a dual-locking ring oscillator
2016 13th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT), 2016An ultra-low power frequency synthesizer based on a 28-nm CMOS dual-voltage controlled ring oscillator is presented. The technological dispersion and temperature effects are tackled thanks to a Delay locked loop (DLL) which sets a coarse tuning voltage.
Yann Deval +3 more
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