Effective features are essential for fault diagnosis.Due to the faint characteristics of a single line-to-ground(SLG)fault,fault line detection has become a challenge in resonant grounding distribution systems.This pa...Effective features are essential for fault diagnosis.Due to the faint characteristics of a single line-to-ground(SLG)fault,fault line detection has become a challenge in resonant grounding distribution systems.This paper proposes a novel fault line detection method using waveform fusion and one-dimensional convolutional neural networks(1-D CNN).After an SLG fault occurs,the first-half waves of zero-sequence currents are collected and superimposed with each other to achieve waveform fusion.The compelling feature of fused waveforms is extracted by 1-D CNN to determine whether the fused waveform source contains the fault line.Then,the 1-D CNN output is used to update the value of the counter in order to identify the fault line.Given the lack of fault data in existing distribution systems,the proposed method only needs a small quantity of data for model training and fault line detection.In addition,the proposed method owns fault-tolerant performance.Even if a few samples are misjudged,the fault line can still be detected correctly based on the full output results of 1-D CNN.Experimental results verified that the proposed method can work effectively under various fault conditions.展开更多
In resonant grounding systems,most single-phaseto-ground faults evolve from IAFs(Intermittent Arc Faults).Earlier detection of IAFs can facilitate fault avoidance.This work proposes a novel method based on machine lea...In resonant grounding systems,most single-phaseto-ground faults evolve from IAFs(Intermittent Arc Faults).Earlier detection of IAFs can facilitate fault avoidance.This work proposes a novel method based on machine learning for detecting IAFs in three steps.First,the feature of zero-sequence current is automatically extracted and selected by a newlydesigned FINET(“For IAFs,Neuron Elaboration Net”),instead of traditional feature selection based on time-frequency decomposition.Moreover,data of the zero-sequence current divided by different time windows are successively input into the trained FINET.A proposed PSF(principal-subordinate factor)analyses the results obtained from FINET to improve anti-interference in the mentioned IAF detection algorithm.Experiments using PSCAD/EMTDC software simulation data show the proposed method is feasible and highly adaptable.In addition,the detection result of on-site recorded data demonstrates the effectiveness of the proposed method in practical resonant grounding systems.展开更多
The reliability of quasi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is studied.Noting rather flat fGn power spectral density(PSD)in most part of frequency band,the fG...The reliability of quasi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is studied.Noting rather flat fGn power spectral density(PSD)in most part of frequency band,the fGn is innovatively regarded as a wide-band process.Then,the stochastic averaging method for quasi integrable Hamiltonian systems under wide-band noise excitation is applied to reduce 2n-dimensional original system into n-dimensional averaged ltd stochastic differential equations(SDEs).Reliability function and mean first passage time are obtained by solving the associated backward Kolmogorov equation and Pontryagin equation.The validity of the proposed procedure is tested by applying it to an example and comparing the numerical results with those from Monte Carlo simulation.展开更多
The scope of this paper broadly spans in two areas： system identification of resonant system and design of an efficient control scheme suitable for resonant systems. Use of filters based on orthogonal basis functions...The scope of this paper broadly spans in two areas： system identification of resonant system and design of an efficient control scheme suitable for resonant systems. Use of filters based on orthogonal basis functions （OBF） have been advocated for modelling of resonant process. Kautz filter has been identified as best suited OBF for this purpose. A state space based system identification technique using Kautz filters, viz. Kautz model, has been demonstrated. Model based controllers are believed to be more efficient than classical controllers because explicit use of process model is essential with these modelling techniques. Extensive literature search concludes that very few reports are available which explore use of the model based control studies on resonant system. Two such model based controllers are considered in this work, viz. model predictive controller and internal model controller. A model predictive control algorithm has been developed using the Kautz model. The efficacy of the model and the controller has been verified by two case studies, viz. linear second order underdamped process and a mildly nonlinear magnetic ball suspension system. Comparative assessment of performances of these controllers in those case studies have been carried out.展开更多
The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14O(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.22 MeV/nuc...The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14O(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.22 MeV/nucleon 17F radioactive ion (RI) beam was produced via a projectile-fragmentation reaction, and separated by a Radioactive Ion Beam Line in Lanzhou (RIBLL). By bombarding a thick (CH2)n target, the energy spectra of the recoiled protons were measured by two ΔE-E silicon telescopes at the center-of-mass scattering angles of θc.m.≈175°±5°, θc.m.≈152°±8°, respectively. Several proton resonances in 18Ne were ob served clearly. A further R-matrix analysis of the experimental data is under way to determine the resonant parameters. The present work reports the preliminary results briefly.展开更多
Geometric nonlinear behaviors ofmicro resonators have attracted extensive attention of MEMS （micro- electro-mechanical systems） researchers, and MEMS transducers utilizing these behaviors have been widely re- search...Geometric nonlinear behaviors ofmicro resonators have attracted extensive attention of MEMS （micro- electro-mechanical systems） researchers, and MEMS transducers utilizing these behaviors have been widely re- searched and used due to the advantages of essentially digital output. Currently, the design of transducers with nonlinear behaviors is mainly performed by numerical method and rarely by system level design method. In this paper, the geometric nonlinear beam structure was modeled and established as a reusable library component by sys- tem level modeling and simulation method MuPEN （multi port element network）. A resonant accelerometer was constructed and simulated using this model together with MuPEN reusable library. The AC （alternating current） analysis results of MuPEN model agreed well with the results of architect model and the experiment results shown in the existing reference. Therefore, we are convinced that the beam component based on MuPEN method is valid, and MEMS system level design method and related libraries can effectively model and simulate transducers with geometric nonlinear behaviors if appropriate system level components are available.展开更多
A silver quadrumer consisting of four parallel aligned rectangular nanobars, with three at the bottom and one at the top, is proposed to provide two Fano resonances. These two resonances can be adjusted either simulta...A silver quadrumer consisting of four parallel aligned rectangular nanobars, with three at the bottom and one at the top, is proposed to provide two Fano resonances. These two resonances can be adjusted either simultaneously or independently simply by tuning the geometrical parameters. Due to the formation of the two resonances in a relatively short wavelength range, one of them can be spectrally squeezed to be very narrow, which induces a very high figure of merit(FoM =45). By decomposing the scattering spectrum into bright modes and dark modes, the double Fano resonances are found to be originated from grouping the unit cells into two different groups. The evolution of the scattering spectrum with the central dimer position along the polarization direction suggests that the symmetry reducing induces the second Fano resonance and improves the Fo M of the first one. By introducing one more nanobar into the quadrumer system, the Fo M can approach the material's limit, although the dip is relatively shallow. The ultrahigh Fo M of the Fano resonance in the proposed quadrumer can provide ultra-sensitive refractive index sensing.Furthermore, the method for providing multiple independently tunable Fano resonances can offer new solutions to designing plasmonic-related nanolasers, photocatalysis, and biochemical sensors, etc.展开更多
We have studied the ππN system and coupled channels by using of the Faddeev equations and two N＊ and one A states, all of them with jR =1/2＋, have been found in the formalism as dynamically generated states. In ad...We have studied the ππN system and coupled channels by using of the Faddeev equations and two N＊ and one A states, all of them with jR =1/2＋, have been found in the formalism as dynamically generated states. In addition, signatures for a new N＊ resonance with JR = 1/2＋ are found around an energy of 1920 MeV in the three-body center of mass system.展开更多
In this talk,I discuss our recent studies of three-hadron systems and the resonances found therein.The studies consist of solving Faddeev equations with the input two body interactions obtained from the chiral Lagrang...In this talk,I discuss our recent studies of three-hadron systems and the resonances found therein.The studies consist of solving Faddeev equations with the input two body interactions obtained from the chiral Lagrangians.The systems which we study are either made of two mesons and a baryon or of three mesons.The motivation for these studies comes from the data on many baryon resonances,especially the ones with J ^π = 1/2 ^＋,which show a large branching ratio to the two meson-one baryon decay channels.In addition to this,several new studies at BES,BELLE,BABAR etc.,claim the existence of new meson resonances which seem to couple strongly to three-meson systems,where mostly two out of the three mesons appear as a known resonance.Hitherto,we have studied two meson-one baryon systems with strangeness =-1,0 and 1 and three-meson systems made of two-pseudoscalars and a vector meson.As we will show in this manuscript,we find many resonances which couple to three-hadrons.展开更多
基金supported by the National Natural Science Foundation of China through the Project of Research of Flexible and Adaptive Arc-Suppression Method for Single-Phase Grounding Fault in Distribution Networks(No.51677030).
文摘Effective features are essential for fault diagnosis.Due to the faint characteristics of a single line-to-ground(SLG)fault,fault line detection has become a challenge in resonant grounding distribution systems.This paper proposes a novel fault line detection method using waveform fusion and one-dimensional convolutional neural networks(1-D CNN).After an SLG fault occurs,the first-half waves of zero-sequence currents are collected and superimposed with each other to achieve waveform fusion.The compelling feature of fused waveforms is extracted by 1-D CNN to determine whether the fused waveform source contains the fault line.Then,the 1-D CNN output is used to update the value of the counter in order to identify the fault line.Given the lack of fault data in existing distribution systems,the proposed method only needs a small quantity of data for model training and fault line detection.In addition,the proposed method owns fault-tolerant performance.Even if a few samples are misjudged,the fault line can still be detected correctly based on the full output results of 1-D CNN.Experimental results verified that the proposed method can work effectively under various fault conditions.
基金sponsored by the National Natural Science Foundation of China (No.51677030).
文摘In resonant grounding systems,most single-phaseto-ground faults evolve from IAFs(Intermittent Arc Faults).Earlier detection of IAFs can facilitate fault avoidance.This work proposes a novel method based on machine learning for detecting IAFs in three steps.First,the feature of zero-sequence current is automatically extracted and selected by a newlydesigned FINET(“For IAFs,Neuron Elaboration Net”),instead of traditional feature selection based on time-frequency decomposition.Moreover,data of the zero-sequence current divided by different time windows are successively input into the trained FINET.A proposed PSF(principal-subordinate factor)analyses the results obtained from FINET to improve anti-interference in the mentioned IAF detection algorithm.Experiments using PSCAD/EMTDC software simulation data show the proposed method is feasible and highly adaptable.In addition,the detection result of on-site recorded data demonstrates the effectiveness of the proposed method in practical resonant grounding systems.
基金supported by National Key R&D Program of China(Grant No.2018 YFC0809400)Zhejiang Provincial Natural Science Foundation of China(Grant No.LY16A020001)National Natural Science Foundation of China(Grant No.11802267).
文摘The reliability of quasi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is studied.Noting rather flat fGn power spectral density(PSD)in most part of frequency band,the fGn is innovatively regarded as a wide-band process.Then,the stochastic averaging method for quasi integrable Hamiltonian systems under wide-band noise excitation is applied to reduce 2n-dimensional original system into n-dimensional averaged ltd stochastic differential equations(SDEs).Reliability function and mean first passage time are obtained by solving the associated backward Kolmogorov equation and Pontryagin equation.The validity of the proposed procedure is tested by applying it to an example and comparing the numerical results with those from Monte Carlo simulation.
文摘The scope of this paper broadly spans in two areas： system identification of resonant system and design of an efficient control scheme suitable for resonant systems. Use of filters based on orthogonal basis functions （OBF） have been advocated for modelling of resonant process. Kautz filter has been identified as best suited OBF for this purpose. A state space based system identification technique using Kautz filters, viz. Kautz model, has been demonstrated. Model based controllers are believed to be more efficient than classical controllers because explicit use of process model is essential with these modelling techniques. Extensive literature search concludes that very few reports are available which explore use of the model based control studies on resonant system. Two such model based controllers are considered in this work, viz. model predictive controller and internal model controller. A model predictive control algorithm has been developed using the Kautz model. The efficacy of the model and the controller has been verified by two case studies, viz. linear second order underdamped process and a mildly nonlinear magnetic ball suspension system. Comparative assessment of performances of these controllers in those case studies have been carried out.
基金supported by the "100 Persons Project" (Grant No. BR091104)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant NO. KJCX2-YW-N32)+1 种基金the National Natural Science Foundation of China (Grant Nos. 10975163 and 11021504) the Major State Basic Research Development Program of China (Grant No. 2007CB815000)
文摘The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14O(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.22 MeV/nucleon 17F radioactive ion (RI) beam was produced via a projectile-fragmentation reaction, and separated by a Radioactive Ion Beam Line in Lanzhou (RIBLL). By bombarding a thick (CH2)n target, the energy spectra of the recoiled protons were measured by two ΔE-E silicon telescopes at the center-of-mass scattering angles of θc.m.≈175°±5°, θc.m.≈152°±8°, respectively. Several proton resonances in 18Ne were ob served clearly. A further R-matrix analysis of the experimental data is under way to determine the resonant parameters. The present work reports the preliminary results briefly.
文摘Geometric nonlinear behaviors ofmicro resonators have attracted extensive attention of MEMS （micro- electro-mechanical systems） researchers, and MEMS transducers utilizing these behaviors have been widely re- searched and used due to the advantages of essentially digital output. Currently, the design of transducers with nonlinear behaviors is mainly performed by numerical method and rarely by system level design method. In this paper, the geometric nonlinear beam structure was modeled and established as a reusable library component by sys- tem level modeling and simulation method MuPEN （multi port element network）. A resonant accelerometer was constructed and simulated using this model together with MuPEN reusable library. The AC （alternating current） analysis results of MuPEN model agreed well with the results of architect model and the experiment results shown in the existing reference. Therefore, we are convinced that the beam component based on MuPEN method is valid, and MEMS system level design method and related libraries can effectively model and simulate transducers with geometric nonlinear behaviors if appropriate system level components are available.
基金National Natural Science Foundation of China(NSFC)(61675070,61378082,11704133)
文摘A silver quadrumer consisting of four parallel aligned rectangular nanobars, with three at the bottom and one at the top, is proposed to provide two Fano resonances. These two resonances can be adjusted either simultaneously or independently simply by tuning the geometrical parameters. Due to the formation of the two resonances in a relatively short wavelength range, one of them can be spectrally squeezed to be very narrow, which induces a very high figure of merit(FoM =45). By decomposing the scattering spectrum into bright modes and dark modes, the double Fano resonances are found to be originated from grouping the unit cells into two different groups. The evolution of the scattering spectrum with the central dimer position along the polarization direction suggests that the symmetry reducing induces the second Fano resonance and improves the Fo M of the first one. By introducing one more nanobar into the quadrumer system, the Fo M can approach the material's limit, although the dip is relatively shallow. The ultrahigh Fo M of the Fano resonance in the proposed quadrumer can provide ultra-sensitive refractive index sensing.Furthermore, the method for providing multiple independently tunable Fano resonances can offer new solutions to designing plasmonic-related nanolasers, photocatalysis, and biochemical sensors, etc.
基金Supported by DGICYT (FIS2006-03438)JSPS-CSIC collaboration agreement (2005JP0002)+1 种基金Grant for ScientificResearch of JSPS (188661)K. P. K thanks the support by the Fundao para a Ciência e a Tecnologia of the Ministé rio da Ciência, Tecnologia e EnsinoSuperior of Portugal (SFRH/BPD/40309/2007)
文摘We have studied the ππN system and coupled channels by using of the Faddeev equations and two N＊ and one A states, all of them with jR =1/2＋, have been found in the formalism as dynamically generated states. In addition, signatures for a new N＊ resonance with JR = 1/2＋ are found around an energy of 1920 MeV in the three-body center of mass system.
基金supported by a FPU grant of the Ministerio de Ciencia y TecnologíaK.P.Khemchandani thanks the support by the Fundaco para a Ciencia e a Tecnologia of the Ministério da Ciencia,Tecnologia e Ensino Superior of Portugal (SFRH/BPD/40309/2007)part of the EU Integrated Infrastructure Initiative Hadron Physics Project under contract number RII3-CT-2004-506078
文摘In this talk,I discuss our recent studies of three-hadron systems and the resonances found therein.The studies consist of solving Faddeev equations with the input two body interactions obtained from the chiral Lagrangians.The systems which we study are either made of two mesons and a baryon or of three mesons.The motivation for these studies comes from the data on many baryon resonances,especially the ones with J ^π = 1/2 ^＋,which show a large branching ratio to the two meson-one baryon decay channels.In addition to this,several new studies at BES,BELLE,BABAR etc.,claim the existence of new meson resonances which seem to couple strongly to three-meson systems,where mostly two out of the three mesons appear as a known resonance.Hitherto,we have studied two meson-one baryon systems with strangeness =-1,0 and 1 and three-meson systems made of two-pseudoscalars and a vector meson.As we will show in this manuscript,we find many resonances which couple to three-hadrons.
