Results 1 to 10 of about 9,007 (253)

Study on stability margin of ultra-low frequency oscillation in hydropower system

Energy Reports, 2023
In recent years, the ultra-low frequency oscillation of power system caused by hydropower units has occurred frequently. It is very important to study the ultra-low frequency oscillation characteristics of hydropower stations for the stable operation of ...
Fan Tang, Yudong Zhang, Xiaobin Liang, Zhengyu Gong, Xin Li, Jiayu Liu, Hang Ru, Jian Sun, Hongxun Li   +8 more
doaj   +4 more sources

The occurrence mechanism and damping method of ultra‐low‐frequency oscillations [PDF]

IET Renewable Power Generation, 2021
The ultra‐low‐frequency oscillation (ULFO) problem has reappeared in China recently. Although the hydraulic generator is supposed to have a strong connection to this problem, the conditions for ULFO appearance and detailed reasons are not clear yet.
Peng Wang, Baohong Li, Qin Jiang, Gang Chen, Xiaoyan Han, Tomislav Dragicevic, Tianqi Liu   +6 more
doaj   +8 more sources

A Robust Design Method for Ultra-Low-Frequency Oscillation Suppression Control in Hydro–Photovoltaic Complementary Systems

Applied Sciences, 2023
Aiming at the problem of ultra-low-frequency oscillation (ULFO) in power systems, with an oscillation frequency lower than 0.1 Hz, an oscillation suppression control method is proposed. Firstly, the mathematical modeling of the system is carried out, and
Xueyang Zeng, Gang Chen, Huabo Shi, Sijia Wang, Peng Shi   +4 more
doaj   +3 more sources

Low frequency oscillation characteristics of East China Power Grid after commissioning of Huai-Hu ultra-high voltage alternating current project

Journal of Modern Power Systems and Clean Energy, 2015
The low frequency oscillation characteristics of East China Power Grid after commissioning of the first ultra-high voltage alternating current (UHVAC) project-the Huai-Hu UHVAC project are studied. Several low frequency oscillation cases occurred in East
Chao Wang, Yang Lv, Hongyang Huang, Jing Zhang, Jihong Li, Yingyi Li, Weizhen Sun, Yong Chang   +7 more
doaj   +3 more sources

A Dual-Mode Memristor-Based Oscillator for Energy-Efficient Biomedical Wireless Systems [PDF]

Micromachines
This paper presents a novel dual-mode memristor-based ring oscillator designed for energy-efficient, wireless biomedical signal conditioning systems.
Imen Barraj, Mohamed Masmoudi
doaj   +2 more sources

Small-Signal Stability Analysis of Photovoltaic-Hydro Integrated Systems on Ultra-Low Frequency Oscillation

Energies, 2020
In recent years, ultralow-frequency oscillation has repeatedly occurred in asynchronously connected regional power systems and brought serious threats to the operation of power grids.
Sijia Wang, Xiangyu Wu, Gang Chen, Yin Xu   +3 more
doaj   +3 more sources

Research on Ultra-Low-Frequency Oscillation Suppression Method of High-Head, Large-Capacity Hydropower Units

Energies
Aiming at the problem of ultra-low-frequency oscillation (ULFO) caused by an irrational setting of governor parameters of high-head hydraulic turbine units, this paper proposes a method to optimize the additional damping control parameters of the ...
Sixiang Zhang, Longyuan Li, Weijun Liu, Daijun Luo, Bingjie Zhai, Haomin He, Peng Zou, Yuhong Wang, Shilin Gao   +8 more
doaj   +3 more sources

A Novel Control Strategy for Hydraulic Turbines to Consider Both Primary Frequency Regulation and Ultra-Low Frequency Oscillation Suppression

Energies
In response to the requirements of mitigating ultra-low frequency oscillation (ULFO) and enhancing primary frequency regulation (PFR) performance in hydropower-dominated systems, a novel control strategy, namely the center-frequency-structured governor ...
Yong Jia, Bangwei Tan, Wentao Zhang, Dongrong Jiang, Chao Yang, Yunhao Wen   +5 more
doaj   +3 more sources

Stark modulated Rydberg dissipative time crystals at room temperature applied to sub-kHz electric field sensing [PDF]

Scientific Reports
Out-of-equilibrium Rydberg gases exhibit emergent many-body phases due to mode competition. Sustained limit cycle oscillations (OSC) emerge when driven by B-fields at room temperature, forming robust Rydberg dissipative time crystals (DTC).
Darmindra Arumugam
doaj   +2 more sources

Ultra-low frequency oscillation analysis and robust fixed order control design

International Journal of Electrical Power and Energy Systems, 2019
Abstract Yunnan Grid, a hydro-dominated system, has experienced many times ultra-low frequency oscillations (ULFO) since the grid is connected to the China Southern Grid via DC ties in 2016. The root cause of the oscillation phenomena is investigated in this work.
Deqiang Gan, Chongxi Jiang, Jinghao Zhou   +2 more
exaly   +2 more sources