检索结果-南通市图书馆

Journal of Modern Power Systems and Clean Energy 2015年第3期3卷 332-340页

作者： Chao WANG Yang LV Hongyang HUANG Jing ZHANG Jihong LI Yingyi LI Weizhen SUN Yong CHANG State Grid Zhejiang Electric Power Company Hangzhou 310007China State Grid Jilin Electric Power Company Changchun 130000China State Grid Operation Company Beijing 100052China

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 China Power Grid in the past few years are reviewed and summarized.Based on the analysis of the different typical operation modes,the main low frequency oscillation modes in East China Power Grid in the early stages of development of ultra-high voltage(UHV)are summarized,and the impacts of the significant power grid maintenance on low frequency oscillation characteristics are analyzed.Besides,the oscillation mode of UHV generators to East China Power Grid is researched,and the importance of the power system stabilizator(PSS)is emphasized.Furthermore,the comparative analysis between the time domain and the frequency domain is carried out,and the influences of the governing system on low frequency oscillation characteristics are revealed.Finally,both the focus and the direction of low frequency oscillation research are presented.

关键词： Ultra-high voltage(UHV) low frequency oscillation Forced oscillation Power system stabilizator(PSS) Governing system

Measurement-based solution for low frequency oscillation analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2016年第3期4卷 406-413页

作者： Chen SHEN Zhi AN Xianzhong DAI Wei WEI Lijie DING Department of Electrical Engineering Tsinghua UniversityBeijingChina State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Tsinghua UniversityBeijingChina Electric Power Research Institute of Sichuan Electric Power Company ChengduChina

This paper presents a measurement-based solution for low frequency oscillation(LFO) analysis in both real time monitoring and off-line case study. An online LFO property discrimination method is developed first,which alternately uses empirical mode decomposition(EMD)/Hilbert transform(HT) and square calculation to process the measurement data. The method magnifies the variation trend of oscillating variables to accurately discriminate the property of the oscillation. Subsequently, an oscillation source locating method for the forced oscillation(FO) and a strongly correlated generator identification method for the weak damping oscillation(WDO) are proposed. Finally, numerical study results on a test system of the isolated Changdu grid in Tibet validate the proposed methods.

关键词： low frequency oscillation oscillation property discrimination oscillation source location Strongly correlated generator identification

The Seasonal Climate and low frequency oscillation in the Simulated Mid-Holocene Megathermal Climate

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2000年第3期17卷 445-457页

作者：王会军 LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing

The mid—Holocene climate about 6000 years ago was simulated by using the atmospheric general circulation model. The orbital parameters for 6 ka BP (before present) were prescribed and other forcing factors were set in the modern conditions. Results show that the large—scale climate change in the African—Asian monsoon areas during the summer—time is strongly compared to the present climate, while the changes in other seasons and regions are generally weak. The results also revealed the change of the low frequency oscillation in the atmosphere. Key words Seasonal climate - low frequency oscillation - Mid—Holocene This research was jointly supported by the National Natural Science Foundation of China (NSFC) key project “ Variation of Paleo—environment over East Asia and Its Dynamic Relation with the Global Change” under contract 49894170 and the NSFC project “ Coupling of the AGCM with an Biome Model and the Simulation on the Mid-Holocene Climate” under contract 49975018.

关键词： Seasonal climate low frequency oscillation Mid—Holocene

A Robust Real-time low-frequency oscillation Detection and Analysis (LFODA) System with Innovative Ensemble Filtering

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2020年第1期6卷 174-183页

作者： Desong Bian Zhe Yu Di Shi Senior Ruisheng Diao Zhiwei Wang GEIRI North America San JoseCA 95134.

low-frequency oscillations are hazardous to power system operation,and can lead to cascading failures if not detected and mitigated in a timely manner.This paper presents a robust and automated real-time monitoring system for detecting grid oscillations and analyzing their mode shapes using PMU measurements.A novel Extended Kalman Filtering(EKF)based approach is introduced to detect and analyze oscillations.To further improve the accuracy and efficiency of the presented software system,the EKF approach takes advantages of three effective signal processing methods(including Prony’s Method,Hankel Total Least Square(HTLS)Method,EKF)and adopts a novel voting schema to significantly reduce the computation cost.Results from these methods are processed through a timeseries filter to ensure the consistency of detected oscillations and reduce the number of false alarms.The Density-based Spatial Clustering of Applications with Noise(DBSCAN)method is used to accurately classify oscillation modes and the PMU measurement channels.The LFODA system has been functioning well in the State Grid Jiangsu Electric Power Company with 176 PMUs and 1000+channels since February 2018,demonstrating outstanding performance in reducing false alarms with much less computational cost.

关键词： Extended Kalman filter HTLS low frequency oscillation PMU Prony

Dust Storms in North China in 2002: A Case Study of the low frequency oscillation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2007年第1期24卷 15-23页

作者：范可王会军 Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 Department of Atmospheric ScienceYunnan UniversityKunming 650091 Graduate University of the Chinese Academy of SciencesBeijing 100039 Department of Atmospheric Science Yunnan UniversityKunming 650091

The low frequency oscillation in both hemispheres and its possible role in the dust weather storm events over North China in 2002 are analyzed as a case study. Results show that the Aleutian low is linked with the Circumpolar Vortex in the Southern Hemisphere on a 30-60-day oscillation, with a weak Circumpolar Vortex tending to deepen the Aleutian low which may be helpful for the generation of dust storm events. The possible mechanism behind this is the inter-hemispheric interaction of the mean meridional circulation, with the major variability over East Asia. The zonal mean westerly wind at high latitudes of the Southern Hemisphere in the upper level troposphere may lead that of the Northern Hemisphere, which then impacts the local circulation in the Northern Hemisphere. Thus, the low frequency oscillation teleconnection is one possible linkage in the coupling between the Southern Hemisphere circulation and dust events over North China. However, the interannual variation of the low frequency oscillation is unclear.

关键词： dust storm events low frequency oscillation mean meridional circulation and local circulation relationship

Analysis of low frequency oscillation and Source Location in Power Systems

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2018年第1期4卷 58-66页

作者： Yinbiao Shu Xiaoxin Zhou Wenfeng Li State Grid Corporation of China Beijing 100031China China Electric Power Research Institute Beijing 100192China State Key Laboratory of Power Grid Safety and Energy Conservation Beijing 100192China

The major problem in current online diagnosis and analysis for power system oscillation is mainly concerned with finding the oscillation source in a fast and correct way using the data collected by the Wide Area Measurement System(WAMS).This paper for the first time proposes a scheme of cut set energy based on WAMS.Independent of accurate parameters,the scheme can make full use of WAMS data based on cut set energy construction and fast calculation to locate the source during oscillation.Afterwards,a scheme of torque decomposition is proposed,based on which the controller’s torque can be divided into damping torque and synchronous torque by calculation through WAMS data,and this paper puts forward the abnormal response and simulation models calibration of influential controllers.Analysis of an oscillation case shows how the cut set energy scheme and the torque decomposition scheme are applied in a real-world power system,and the schemes are proven to be reliable and practical in identifying and locating oscillation sources.

关键词： Cut set energy low frequency oscillation model calibration oscillation source power system torque decomposition

A Disturbance Source Location Method on the low frequency oscillation With Time-varying Steady-state Points

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CES Transactions on Electrical Machines and Systems 2018年第2期2卷 226-231页

作者： Xiangxin Li Ming Zhou Yazhou Luo 不详 Electrical Engineering from North China Electricity Power University(NCEPU)

The low frequency oscillation is a serious threat to security and stability of a power grid.How to locate the disturbance source accurately is an important issue to low frequency oscillation disposal.Existing methods have poor adaptability to the low frequency oscillation with time-varying steady-state points because of the limitations in the location criterion derivation.A disturbance source location method on a low frequency oscillation with good generality is presented in the paper.Firstly,the reasons why the steady-state points are time-varying on a low frequency oscillation are analyzed.Then,based on the energy function construction form,the branch transmission energy is decomposed into state energy,reciprocating energy and dissipation energy by mathematical derivation.The flow direction of the dissipation energy shows the source and destination of the disturbance energy,and the specific location of a disturbance source can be identified according to its flow direction.Meanwhile,to meet the needs of energy calculation,a recognition method on the electrical quantities steady-state points is also presented by using the cubic spline interpolation.Simulation results show the correctness of the derivation and analysis on energy structure in the paper,and the disturbance source can be located accurately according to the dissipation energy.

关键词： dissipation energy disturbance source location energy decomposition low frequency oscillation steady-state point identification

Global Governor-side Damping Controller for low frequency oscillation of Power Systems Based on Partial State Feedback

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Global Governor-side Damping Controller for Low Frequency Os...

Influence of Virtual Synchronous Generators on low frequency oscillations

2010 Chinese Control and Decision Conference

作者： Ancheng Xue~1,Pinghua An~(1,2),Tianshu Bi~1 1.Key Laboratory of Power System Protection and Dynamic Security Monitoring and Control,Ministry of Education School of Electrical and Electronic Engineering,North China Electric Power University,Beijing 102206 China 2.Extra-High Voltage Company,Jiangxi Electric Power Company,Nanchang 330006,China

low frequency oscillation(LFO) is harmful to power system security and stability.The traditional solutions for LFO are the power system stabilizer(PSS) with local or global signal implemented on the excitations.This paper explores the global governor-side damping controllers for LFO,i.e.,controller with input from the wide area measurement system(WAMS).Design strategy of global governor-side damping controller with remote signal from WAMS is proposed,based on the partial state feedback theory.Simulation results in a 4-generator-2-area power system show the effectiveness of the proposed global governor-side damping controller.

关键词： low frequency oscillation Damping Controller Wide Area Measurement System（WAMS） Governor Partial State Feedback

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2022年第4期8卷 1029-1038页

作者： Hui Liu Dawei Sun Feng Zhao Yunfeng Tian Peng Song Xuekun Cheng State Grid Wind-Photovoltaic-Energy Storage Hybrid Power Generation Technology Laboratory and State Grid Jibei Electric Power Research Institute(North China Electric Power Research Insititute Co.Ltd) Beijing 100045China State Grid Xinyuan Zhangjiakou Wind PhotovoltaicStorage and Transmission Pilot Power Station Co.LtdZhangjiakou 075000China

By simulating the operating dynamics of synchronous generators(SGs),the use of virtual synchronous gen-rators(VSGs)can help overcome inverter-based generators'shortcomings of low inertia and minimal damping for gridforming applications.VSGs'stability are very important for their solar and wind electricity applications.Currently,the related research primarily focuses on VSGs and their applications for microgrids.There has been little research to explore how VSGs effect low frequency oscillations in power transmission systems.This paper describes a small-signal model of a VSGSG interconnected system,which is suitable for studying low frequency oscillation damping in a power transmission grid.Based on this model,the effects of VSGs on low frequency oscillations are compared with the effects of SGs to reveal the mechanism of how VSGs infuence damping characteristics.The influence of each VSG control loop on oscillations is also analyzed in this paper.Then,the low frequency oscillation risks with different types of VSGs are described.Finally,experiments on a real-time laboratory(RT-LAB)platform are conducted to verify the small-signal analysis results.

关键词： Grid-forming inverters low frequency oscillation participation factor renewable electricity small-signal model virtual synchronous generator(VSG)

Effect of high-pressure detonation products on fuel injection and propagation characteristics of detonation wave

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Propulsion and Power Research 2022年第1期11卷 58-73页

作者： Gaoyang Ge Li Deng Hu Ma Zhenjuan Xia Xiao Liu Changsheng Zhou School of Mechanical Engineering Nanjing University of Science and TechnologyNanjingJiangsu210094China Institute of Chemical Materials China Academy of Engineering PhysicsMianyangSichuan621999China College of Power and Energy Engineering Harbin Engineering UniversityHarbinHeilongjiang150001China

The effect of high-pressure detonation products on fuel injection and propagation characteristics of detonation wave has been investigated in the form of ion voltage by varying the equivalence ratio(ER),air mass flux,and operation duration with hydrogen-air mixtures.It has been shown experimentally that the ion voltage decays gradually during the initial stage of rotating detonation wave(RDW).The attenuation of ion voltage is a general phenomenon,and the decay rate of ion voltage and its peak value of the trough state are related to the equivalence ratio and air mass flux.The analysis of interaction between the combustor and hydrogen plenum indicates that the feedback of high-pressure detonation products leads to the attenuation of ion voltage.In addition,the long-duration tests show that the ion voltage will recover to a steady state with the extension of reaction time,when the purgation(products leaving plenums)of detonation products is greater than feedback(products entering plenums)of detonation products in the hydrogen plenum.The recovery of ion voltage starts earlier at the higher equivalence ratio and air mass flux,and the peak value of ion voltage in the steady state also increases with the increase of equivalence ratio and air mass flux.A low frequency oscillation about 10 e12 Hz occurs in the RDW at some operation conditions.This low frequency oscillation is related to the interaction between the combustor and hydrogen plenum,and can be eliminated by either increasing the equivalence ratio or decreasing the air mass flux.

关键词： High-pressure detonation products Ion voltage Feedback Purgation Long-duration test low frequency oscillation