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Two-Photon Excited State Dynamics of Dark Rydberg and Bright Valence States in Furan
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作者 龙金友 胡春龙 张冰 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第4期26-29,共4页
Two-photon absorption in systems with parity permits access to states that cannot be directly prepared by one-photon absorption. Here we investigate ultrafast internal conversion (IC) dynamics of furan by using this... Two-photon absorption in systems with parity permits access to states that cannot be directly prepared by one-photon absorption. Here we investigate ultrafast internal conversion (IC) dynamics of furan by using this strategy in combination with femtosecond time-resolved photoelectron imaging. The dark Rydberg S1 and bright valence S2 states are simultaneously excited by two photons of 405 nm, and then ionized by two photons of 800nm. The IC from S2 to S1 is clearly observed and extracted from the time dependence of the higher photoelectron kinetic energy (PKE) component. More importantly, the internal conversions to hot So from directly-prepared S1 and secondarily-populated S1 are unambiguously identified by the time-dependence of the lower PKE component. The average lifetime of the S2 and S1 states is measured to be 29 fs. The internal conversions of S2 to S1, S1 to hot So occur on estimated timescales of 15.4 fs and 38 fs, respectively. 展开更多
关键词 SI Two-Photon Excited State Dynamics of Dark Rydberg and Bright Valence states in Furan
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RESEARCH ON A DYNAMICAL MACRO ECONOMIC MODEL BASED ON SIDRAUSKI MODEL
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作者 Tang Jianping Xu JiupingDept.of Appl.Math.,Sichuan Univ.,Chengdu 610065. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2001年第1期95-105,共11页
This paper formulates a kind of dynamical macro economic model based on Sidrauski's work,then presents the sufficient and necessary conditions of the stability of model at equilibrium states,and shows some result... This paper formulates a kind of dynamical macro economic model based on Sidrauski's work,then presents the sufficient and necessary conditions of the stability of model at equilibrium states,and shows some results for special production functions. 展开更多
关键词 dynamical systems equilibrium states consumption level stock of capital money holding.
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Vehicle Dynamic State Estimation: State of the Art Schemes and Perspectives 被引量:11
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作者 Hongyan Guo Dongpu Cao +3 位作者 Hong Chen Chen Lv Huaji Wang Siqi Yang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第2期418-431,共14页
Next-generation vehicle control and future autonomous driving require further advances in vehicle dynamic state estimation. This article provides a concise review, along with the perspectives, of the recent developmen... Next-generation vehicle control and future autonomous driving require further advances in vehicle dynamic state estimation. This article provides a concise review, along with the perspectives, of the recent developments in the estimation of vehicle dynamic states. The definitions used in vehicle dynamic state estimation are first introduced, and alternative estimation structures are presented. Then, the sensor configuration schemes used to estimate vehicle velocity, sideslip angle, yaw rate and roll angle are presented. The vehicle models used for vehicle dynamic state estimation are further summarized, and representative estimation approaches are discussed. Future concerns and perspectives for vehicle dynamic state estimation are also discussed. 展开更多
关键词 Estimation structure extended Kalman filter sensor configuration sideslip angle estimation vehicle dynamic state estimation vehicle dynamics model
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Variable dimensional state space based global path planning for mobile robot 被引量:1
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作者 张浩杰 陈慧岩 +6 位作者 姜岩 龚建伟 熊光明 陈慧岩 姜岩 龚建伟 熊光明 《Journal of Beijing Institute of Technology》 EI CAS 2012年第3期328-335,共8页
A variable dimensional state space(VDSS) has been proposed to improve the re-planning time when the robotic systems operate in large unknown environments.VDSS is constructed by uniforming lattice state space and gri... A variable dimensional state space(VDSS) has been proposed to improve the re-planning time when the robotic systems operate in large unknown environments.VDSS is constructed by uniforming lattice state space and grid state space.In VDSS,the lattice state space is only used to construct search space in the local area which is a small circle area near the robot,and grid state space elsewhere.We have tested VDSS with up to 80 indoor and outdoor maps in simulation and on segbot robot platform.Through the simulation and segbot robot experiments,it shows that exploring on VDSS is significantly faster than exploring on lattice state space by Anytime Dynamic A*(AD*) planner and VDSS is feasible to be used on robotic systems. 展开更多
关键词 variable dimensional state space lattice state space Anytime Dynamic A*(AD*) path planning
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THEORETICAL INVESTIGATION ON STATE OF LOAD DISTRIBUTION AMONG CONTACT BEARINGS OF DOUBLE CIRCULAR ARC HELICAL GEARS 被引量:3
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作者 Wu Baolin (Gear Research Institute, Taiyuan University of Technology) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2000年第2期108-113,共6页
A dynamic analysis approcach to investigate the state of load distribution among contact bearings of double circular are belical gears is proposed and a computer program is developed for calculating the factor of iced... A dynamic analysis approcach to investigate the state of load distribution among contact bearings of double circular are belical gears is proposed and a computer program is developed for calculating the factor of iced distribution based on the theory of W-N gears. The changing situations of load distribution among contact bearings of the gears influenced by main issues are analyzed by a series of parametric studies. 展开更多
关键词 Double circular are belical gears State of load distribution Factor of load distribution Dynamic analysis
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Mathematical analysis of organic-pass transistor using pseudo-p-OTFTs
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作者 Shagun Pal Brijesh Kumar 《Journal of Semiconductors》 EI CAS CSCD 2020年第6期71-77,共7页
Steady state behavior analysis of organic thin film transistor(OTFTs)has been thoroughly researched in the past few decades.Yet,this static logic analysis has drawbacks of high power dissipation and high power consump... Steady state behavior analysis of organic thin film transistor(OTFTs)has been thoroughly researched in the past few decades.Yet,this static logic analysis has drawbacks of high power dissipation and high power consumption,and a large number of prerequisites in the number of transistors for the digital logic circuit application.Hence,to overcome these basic fundamental drawbacks of static logic,the dynamic logic study of organic thin film transistor has been analyzed in this paper.The fundamental basic of dynamic logic is a pass transistor for which logic high and logic low model is designed at an operating voltage of 5 V and frequency of 5 kHz.Additionally,the novel approach of analytical model for organic pass transistor(OPT)circuit is included and verified using MATLAB.The transient individualities of organic pass transistor OPT are examined through Atlas 2-D numerical device simulator.The reduction in the power dissipation along with additional voltage scaling and reduction in the clock frequency such as pipelining may further enable the applications into more complex VLSI ICs. 展开更多
关键词 organic-pass transistor(OPT) logic high logic low pseudo-p dynamic state analytical model
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Recurrence anomaly of ground water behavior before strong earthquakes in North China
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作者 CAO Xin-lai(曹新来) +1 位作者 BIAN Qing-kai(边庆凯) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第z1期163-171,共9页
By analyzing the relationship between ground water behavior and strong seismic activity during the past more than 20 years in North China, we have found similar water level descending variation of a part of wells in ... By analyzing the relationship between ground water behavior and strong seismic activity during the past more than 20 years in North China, we have found similar water level descending variation of a part of wells in the short-term stage before several strong earthquakes. The characteristics of anomaly are: at the beginning, water level dropped abruptly or accelerated to drop; then it turned to slow rising with a smaller amplitude than that of descending; earthquakes occurred during the slow-rising process of water level, and at that time or before earthquake occurrence, water level rose with a large amplitude. Among more than 100 wells in North China, the descending anomalies were not recorded for many times, but similar variation processes of water level were noted at different wells before several strong earthquakes, which proves that seismic precursory anomalies of ground water are of certain recurrence features, occurring repeatedly before different strong earthquakes. Therefore, it is necessary to study the genesis of this type of anomaly and its relationship with strong seismic activity. 展开更多
关键词 North China strong earthquake dynamic state of water level short-term stage RECURRENCE
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Ultrafast Excited State Dynamics of Biliverdin Dimethyl Ester Coordinate with Zinc Ions
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作者 Zhuang Chen Yang-yi Liu +1 位作者 Xiao-xiao He Jin-quan Chen 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第1期69-74,I0030-I0033,共10页
As one of the biological endogenous pigments,biliverdin(BV)and its dimethyl ester(BVE)have extremely weak uorescence in solution with quantum yield less than 0.01%.However,the situation reverses with the addition of z... As one of the biological endogenous pigments,biliverdin(BV)and its dimethyl ester(BVE)have extremely weak uorescence in solution with quantum yield less than 0.01%.However,the situation reverses with the addition of zinc ions.The strength for uorescence of BVE-Zn^2+ complex is greatly enhanced and uorescence quantum yield can increase to5%.Herein,we studied ultrafast excited state dynamics of BVE-Zn^2+ complex in ethanol,npropanol,and DMSO solutions in order to reveal the mechanism of uorescence quantum yield enhancement.The results show that BVE can form a stable coordination complex with zinc with 1:1 stoichiometry in solution.BVE is structurally and energetically more stable in the complex.Using picosecond time-resolve uorescence and femtosecond transient absorption spectroscopy,we show that smaller non-radiative rate constant of BVE-Zn^2+ complex in DMSO is the key to increasing its uorescence quantum yield and the excited state decay mechanism is also revealed.These results provide valuable information about the uorescence property change after BVE binding to metal ions and may provide a guidance for the study of phytochromes or other uorescence proteins in which BV/BVE acts as chromophores. 展开更多
关键词 BILIVERDIN ZINC FLUORESCENCE Quantum yield Femtosecond transient absorption Excited state dynamics
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SELECTION OF STATE VARIABLES AND CONSTRUCTION OF STATE EQUATIONS
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作者 胡允祥 《Journal of China Textile University(English Edition)》 EI CAS 1991年第3期65-76,共12页
In modern control engineering and simulations,it is perferable to get the governing equationsby an easier way,so that state equations have been widely used.There are many rules to select statevariables,but the uses of... In modern control engineering and simulations,it is perferable to get the governing equationsby an easier way,so that state equations have been widely used.There are many rules to select statevariables,but the uses of these rules may have different forms of limitations and exceptions,yet afully argumented bond graph can be processed in proper way to select the state variables and toyield the state equations.The state variables are usually related to the energy-storing elements.State equations can easily be derived from bond graph by means of constitutive relations and struc-tural relations. 展开更多
关键词 dynamics state VARIABLES system dynamics bond GRAPH
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Alternation in F-wave parameters of median nerve from unaffected extremity in stroke patients with hemiplegia under dynamic state
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作者 Hang Zhao Yong Lin Wenhua Qi Shuping Yin Jiachun Feng 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第9期806-808,共3页
BACKGROUND: For many years, the extremities of stroke patients are divided into affected side and unaffected side according to clinical symptoms and body signs. Moreover, previous rehabilitation function training is d... BACKGROUND: For many years, the extremities of stroke patients are divided into affected side and unaffected side according to clinical symptoms and body signs. Moreover, previous rehabilitation function training is developed simply aiming to the dysfunction manifested by unaffected extremity. Problems of unaffected extremity are always ignored, such as left- and right- side connection dysfunction, abnormal muscular tension of unaffected side and so on. OBJECTIVE: To observe neurophysiological change characteristics of unaffected extremity of stroke patients with hemiplegia by electromyographical method. DESIGN: Case-control observation. SETTING: First Hospital, Jilin University. PARTICIPANTS: Eighty stroke patients with hemiplegia confirmed by skull CT or MRI, who firstly hospitalized in the Department of Neurology, First Hospital, Jilin University between July 2004 and March 2005, were retrieved. They were scored > 8 points in Glasgow Coma Scale and had stable vital sign. Nineteen normal persons who received healthy examination in the clinic were involved in normal control group. Following the classification criteria of Brunnstrom's Recovery Stages of Stroke (BRSS), 80 stroke patients with hemiplegia were assigned into 3 groups: BRSS Ⅰ-Ⅱ group (n =36), BRSS Ⅲ-Ⅳ group (n =23) and BRSSⅤ-Ⅵ (n =21). METHODS: F-wave parameters of median nerve of unaffected extremity were detected by electromyographical technique. The recording electrode (muscular belly of abductor pollicis brevis) and reference electrode (first finger bone) were connected with grounding electrode. Stimulating electrode was placed in the median part of wrist joint with stimulation intensity of 130% that of threshold stimulation, stimulation frequency of 2 Hz, current pulse width of 0.2 ms, time course of 5 ms and sensitivity of 2 mV. The F-wave of median nerve of affected extremity under the resting stage (static status) and that of unaffected extremity under the maximum resistant contracted state were detected in order. The amplitude and appearance percentage of F wave were recorded. MAIN OUTCOME MEASURES: Comparison of F-wave parameters of median nerve between the unaffected extremity of stroke patients with hemiplegia and the extremity of control subjects under different status. RESULTS: All the patients accomplished the detection, and all of them participated in the final analysis. ①Under dynamic status, the amplitude and appearance percentage of F wave of unaffected extremity of patients in BRSS Ⅲ-Ⅳ group were significantly higher than those in the normal control group, respectively[(0.803 9±0.157 3) mV vs. (0.406 7±0.170 3) mV; (0.856 1±0.266 8)% vs. (0.650 0±0.197 6)%, P < 0.05]. Under static status, there were no significant differences in F-wave parameters of median nerve in the unaffected extremity of patients between BRSS Ⅰ-Ⅱ group and BRSS Ⅴ-Ⅵ group (P > 0.05). ②F-wave parameters of median nerve of unaffected extremity of patients in BRSS Ⅰ-Ⅱ group and BRSS Ⅴ-Ⅵ group under dynamic statewere higher than those under static status, without significant difference (P > 0.05), while the amplitude and appearance percentage of F wave of median nerve of unaffected extremity of patients in BRSS Ⅲ-Ⅳ group under dynamic statewere significantly higher than those under static state[(0.803 9±0.157 3) mV vs. (0.391 7±0.131 6) mV; (0.856 1±0.266 8 )% vs.(0.639 1 ±0.259 4)%,P < 0.05]. ③ There was no significant difference in F wave parameters among groups under static state(P > 0.05). However, under dynamic status, the amplitude and appearance percentage of F wave parameters of median nerve of unaffected extremity of patients in BRSS Ⅲ-Ⅳ group [(0.803 9±0.157 3) mV,(0.856 1±0.266 8)%] were significantly lower than those in the other two groups [(0.395 1±0.148 8),(0.437 1±0.157 6) mV;(0.612 5±0.232 8)%,(0.657 1±0.232 5)%,P < 0.05]. CONCLUSION: With the development of disease condition and the increase of muscular tension at anesthetic side, combination motor of affected extremity is caused following movement and muscular tension enhances to non-anesthetic-side. Therefore, F-wave parameters increase under dynamic status. 展开更多
关键词 WAVE Alternation in F-wave parameters of median nerve from unaffected extremity in stroke patients with hemiplegia under dynamic state
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Investigation of the Short-Time Photodissociation Dynamics of Furfural in S2 State by Resonance Raman and Quantum Chemistry Calculations
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作者 Kemei Pei Yueben Dong Lei Chen 《Computers, Materials & Continua》 SCIE EI 2018年第4期189-200,共12页
Raman(resonance Raman,FT-Raman),IR and UV-visible spectroscopy and quantum chemistry calculations were used to investigate the photodissociation dynamics of furfural in S2 state.The resonance Raman(RR)spectra indicate... Raman(resonance Raman,FT-Raman),IR and UV-visible spectroscopy and quantum chemistry calculations were used to investigate the photodissociation dynamics of furfural in S2 state.The resonance Raman(RR)spectra indicate that the photorelaxation dynamics for the S0→S2 excited state is predominantly along nine motions:C=O stretchν5(1667 cm-1),ring C=C antisymmetric stretchν6(1570 cm-1),ring C=C symmetric stretchν7(1472 cm-1),C2-O6-C5 symmetric stretch/C1-H8 rock in planeν8(1389 cm-1),C3-C4 stretch/C1-H8 rock in planeν9(1370 cm-1),C5-O6 stretch in planeν12(1154 cm-1),ring breathν13(1077 cm-1),C3-C4 stretchν14(1020 cm-1),C3-C2-O6 symmetric stretchν16(928 cm-1).Stable structures of S0,S1,S2,T1 and T2 states with Cs point group were optimized at CASSCF method in Franck-Condon region there are S2/S1 conical intersection was found by state average method and RR spectra. 展开更多
关键词 FURFURAL resonance Raman quantum chemistry calculation excited state structural dynamics
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Dynamics of Quantum State and Effective Hamiltonian with Vector Differential Form of Motion Method
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作者 熊龙 庄伟峰 龚明 《Chinese Physics Letters》 SCIE EI CAS CSCD 2022年第7期36-40,共5页
Effective Hamiltonians in periodically driven systems have received widespread attention for realization of novel quantum phases, non-equilibrium phase transition, and Majorana mode. Recently, the study of effective H... Effective Hamiltonians in periodically driven systems have received widespread attention for realization of novel quantum phases, non-equilibrium phase transition, and Majorana mode. Recently, the study of effective Hamiltonian using various methods has gained great interest. We consider a vector differential equation of motion to derive the effective Hamiltonian for any periodically driven two-level system, and the dynamics of the spin vector are an evolution under the Bloch sphere. Here, we investigate the properties of this equation and show that a sudden change of the effective Hamiltonian is expected. Furthermore, we present several exact relations, whose expressions are independent of the different starting points. Moreover, we deduce the effective Hamiltonian from the high-frequency limit, which approximately equals the results in previous studies. Our results show that the vector differential equation of motion is not affected by a convergence problem, and thus, can be used to numerically investigate the effective models in any periodic modulating system. Finally, we anticipate that the proposed method can be applied to experimental platforms that require time-periodic modulation, such as ultracold atoms and optical lattices. 展开更多
关键词 Dynamics of Quantum State and Effective Hamiltonian with Vector Differential Form of Motion Method HAMILTONIAN VECTOR QUANTUM
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BTT autopilot design for agile missiles with aerodynamic uncertainty
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作者 Yueyue Ma Jie Guo Shengjing Tang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第4期802-812,共11页
The approach to the synthesis of autopilot with aerody- namic uncertainty is investigated in order to achieve large maneu- verability of agile missiles. The dynamics of the agile missile with reaction-jet control syst... The approach to the synthesis of autopilot with aerody- namic uncertainty is investigated in order to achieve large maneu- verability of agile missiles. The dynamics of the agile missile with reaction-jet control system (RCS) are presented. Subsequently, the cascade control scheme based on the bank-to-turn (B-I-T) steering technique is described. To address the aerodynamic un- certainties encountered by the control system, the active distur- bance rejection control (ADRC) method is introduced in the autopi- lot design. Furthermore, a compound controller, using extended state observer (ESO) to online estimate system uncertainties and calculate derivative of command signals, is designed based on dynamic surface control (DSC). Nonlinear simulation results show the feasibility of the proposed approach and validate the robust- ness of the controller with severe unmodeled dynamics. 展开更多
关键词 agile missile AUTOPILOT high angle of attack active dis-turbance rejection control (ADRC) dynamic surface control (DSC) extended state observer (ESO).
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Analysis of Higher Order System with Impulse Exciting Functions in Z-Domain
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作者 Branislav Dobrucký Pavol Štefanec +2 位作者 Mariana Beňová Oleg V. Chernoyarov Michal Pokorný 《Circuits and Systems》 2016年第11期3951-3970,共20页
This paper deals with mathematical modelling of impulse waveforms and impulse switching functions used in electrical engineering. Impulse switching functions are later investigated using direct and inverse z-transform... This paper deals with mathematical modelling of impulse waveforms and impulse switching functions used in electrical engineering. Impulse switching functions are later investigated using direct and inverse z-transformation. The results make possible to present those functions as infinite series expressed in pure numerical, exponential or trigonometric forms. The main advantage of used approach is the possibility to calculate investigated variables directly in any instant of time;dynamic state can be solved with the step of sequences (T/6, T/12) that means very fast. Theoretically derived waveforms are compared with simulation worked-out results as well as results of circuit emulator LT spice which are given in the paper. 展开更多
关键词 Impulse Systems Switching Function Z-Transformation Inverse Z-Transformation Steady State Operation dynamical State Model Modelling and Simulation
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VEHICLE DYNAMIC ANALYSIS SIMULATION-MODELLING THEORY AND ENGINEERING APPLICATION
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作者 Ju Naijun(Institute of Computer Application, COI) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1995年第1期6-14,共17页
A computer software named VDAS (Vehicle Dynamic Analysis Simulation) is presented.Based on the mathematical modelling for a military vehicle as a 3-D dynamic system, the softwarecreates random excitation resulting fro... A computer software named VDAS (Vehicle Dynamic Analysis Simulation) is presented.Based on the mathematical modelling for a military vehicle as a 3-D dynamic system, the softwarecreates random excitation resulting from double side road-surface roughness by statisticalsimulation, and solves for the time series of the system response from the system state equations,and gives out the results in probability statistics as well as performance evaluations. 展开更多
关键词 Vehicle dynamic system Random excitation State equation Statisticalsimulation
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Resilient Smart Power Grid Synchronization Estimation Method for System Resilience with Partial Missing Measurements
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作者 Yi Wang Yanxin Liu +3 位作者 Mingdong Wang Venkata Dinavahi Jun Liang Yonghui Sun 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第3期1307-1319,共13页
With the increasing demand for power system stability and resilience,effective real-time tracking plays a crucial role in smart grid synchronization.However,most studies have focused on measurement noise,while they se... With the increasing demand for power system stability and resilience,effective real-time tracking plays a crucial role in smart grid synchronization.However,most studies have focused on measurement noise,while they seldom think about the problem of measurement data loss in smart power grid synchronization.To solve this problem,a resilient fault-tolerant extended Kalman filter(RFTEKF)is proposed to track voltage amplitude,voltage phase angle and frequency dynamically.First,a threephase unbalanced network’s positive sequence fast estimation model is established.Then,the loss phenomenon of measurements occurs randomly,and the randomness of data loss’s randomness is defined by discrete interval distribution[0,1].Subsequently,a resilient fault-tolerant extended Kalman filter based on the real-time estimation framework is designed using the timestamp technique to acquire partial data loss information.Finally,extensive simulation results manifest the proposed RFTEKF can synchronize the smart grid more effectively than the traditional extended Kalman filter(EKF). 展开更多
关键词 Dynamic state estimation Kalman filter partial missing measurements power systems smart grid synchronized measurements
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A STATE SPACE ISOMORPHISM THEOREM F0R MINIMAL DYNAMICAL SYSTEMS
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作者 W.P.DAYAWANSA C.F.MARTIN D.CHENG 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1991年第1期34-37,共4页
Consider a discrete time dynamical system x_(k+1)=f(x_k) on a compact metric space M, wheref: M→M is a continuous map. Let h:M→R^k be a continuous output function. Suppose that all ofthe positive orbits of f are den... Consider a discrete time dynamical system x_(k+1)=f(x_k) on a compact metric space M, wheref: M→M is a continuous map. Let h:M→R^k be a continuous output function. Suppose that all ofthe positive orbits of f are dense and that the system is observable. We prove that any outputtrajectory of the system determines f and h and M up to a homeomorphism.If M is a compactAbelian topological group and f is an ergodic translation, then any output trajectory determinesthe system up to a translation and a group isomorphism of the group. 展开更多
关键词 A STATE SPACE ISOMORPHISM THEOREM F0R MINIMAL dynamical SYSTEMS LIM
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Time-domain Dynamic State Estimation for Unbalanced Three-phase Power Systems
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作者 Martin Pfeifer Felicitas Mueller +3 位作者 Steven de Jongh Frederik Gielnik Thomas Leibfried Sören Hohmann 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2023年第2期446-454,共9页
In this paper,we present a time-domain dynamic state estimation for unbalanced three-phase power systems.The dynamic nature of the estimator stems from an explicit consideration of the electromagnetic dynamics of the ... In this paper,we present a time-domain dynamic state estimation for unbalanced three-phase power systems.The dynamic nature of the estimator stems from an explicit consideration of the electromagnetic dynamics of the network,i.e.,the dynamics of the electrical lines.This enables our approach to release the assumption of the network being in quasi-steady state.Initially,based on the line dynamics,we derive a graphbased dynamic system model.To handle the large number of interacting variables,we propose a port-Hamiltonian modeling approach.Based on the port-Hamiltonian model,we then follow an observer-based approach to develop a dynamic estimator.The estimator uses synchronized sampled value measurements to calculate asymptotic convergent estimates for the unknown bus voltages and currents.The design and implementation of the estimator are illustrated through the IEEE 33-bus system.Numerical simulations verify the estimator to produce asymptotic exact estimates,which are able to detect harmonic distortion and sub-second transients as arising from converterbased resources. 展开更多
关键词 Dynamic state estimation power system HARMONIC OBSERVER port-Hamiltonian system static state estimation transient
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Dynamic State Estimation of Power Systems with Uncertainties Based on Robust Adaptive Unscented Kalman Filter
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作者 Dongchen Hou Yonghui Sun +2 位作者 Jianxi Wang Linchuang Zhang Sen Wang 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2023年第4期1065-1074,共10页
In this paper,a robust adaptive unscented Kalman filter(RAUKF)is developed to mitigate the unfavorable effects derived from uncertainties in noise and in the model.To address these issues,a robust M-estimator is first... In this paper,a robust adaptive unscented Kalman filter(RAUKF)is developed to mitigate the unfavorable effects derived from uncertainties in noise and in the model.To address these issues,a robust M-estimator is first utilized to update the measurement noise covariance.Next,to deal with the effects of model parameter errors while considering the computational complexity and real-time requirements of dynamic state estimation,an adaptive update method is produced.The proposed method is integrated with spherical simplex unscented transformation technology,and then a novel derivative-free filter is proposed to dynamically track the states of the power system against uncertainties.Finally,the effectiveness and robustness of the proposed method are demonstrated through extensive simulation experiments on an IEEE 39-bus test system.Compared with other methods,the proposed method can capture the dynamic characteristics of a synchronous generator more reliably. 展开更多
关键词 Dynamic state estimation Kalman filter synchronous generator unscented transformation robust estimation
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Dynamic State Estimation for DFIG with Unknown Inputs Based on Cubature Kalman Filter and Adaptive Interpolation
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作者 Maolin Zhu Hao Liu +3 位作者 Junbo Zhao Bendong Tan Tianshu Bi Samson Shenglong Yu 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2023年第4期1086-1099,共14页
Dynamic state estimation(DSE)accurately tracks the dynamics of power systems and demonstrates the evolution of the system state in real time.This paper proposes a DSE approach for a doubly-fed induction generator(DFIG... Dynamic state estimation(DSE)accurately tracks the dynamics of power systems and demonstrates the evolution of the system state in real time.This paper proposes a DSE approach for a doubly-fed induction generator(DFIG)with unknown inputs based on adaptive interpolation and cubature Kalman filter(AICKF-UI).DFIGs adopt different control strategies in normal and fault conditions;thus,the existing DSE approaches based on the conventional control model of DFIG are not applicable in all cases.Consequently,the DSE model of DFIGs is reformulated to consider the converter controller outputs as unknown inputs,which are estimated together with the DFIG dynamic states by an exponential smoothing model and augmented-state cubature Kalman filter.Furthermore,as the reporting rate of existing synchro-phasor data is not sufficiently high to capture the fast dynamics of DFIGs,a large estimation error may occur or the DSE approach may diverge.To this end,in this paper,a local-truncation-error-guided adaptive interpolation approach is developed.Extensive simulations conducted on a wind farm and the modified IEEE 39-bus test system show that the proposed AICKF-UI can(1)effectively address the divergence issues of existing cubature Kalman filters while being computationally more efficient;(2)accurately track the dynamic states and unknown inputs of the DFIG;and(3)deal with various types of system operating conditions such as time-varying wind and different system faults. 展开更多
关键词 Adaptive interpolation cubature Kalman filter doubly-fed induction generator(DFIG) dynamic state estimation unknown input
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