检索结果-内蒙古大学图书馆

Real-time Synchrophasor Data Compression Technique with Phasor interpolation and extrapolation

Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 803-815页

作者： Fang Zhang Meiqian Liu Zixuan Zhang Jinghan He Wenzhong Gao School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China Department of Electrical and Computer Engineering University of DenverDenverColorado80208USA IEEE

To completely eliminate the time delays caused by phasor data compressions for real-time synchrophasor applications,a real-time synchrophasor data compression(RSDC)is proposed in this *** two-way rotation characteristic and elliptical trajectory of dynamic synchrophasors are introduced first to enhance the compressions along with a fast solving method for elliptical trajectory fitting *** RSDC for phasor data compression and reconstruction is then proposed by combining the interpolation and extrapolation *** proposed RSDC is verified by both the actual phasor measurement data recorded in a two-phase short-circuit incident and a subsynchronous oscillation incident,and the synthetic dynamic *** is also compared with two previous real-time phasor data compression techniques,i.e.,phasor swing door trending(PSDT)and exception and swing door trending(SDT)data compression(ESDC).The verification results demonstrate that RSDC can achieve significantly higher compression ratios for offline applications with the interpolation and the zero-delay phasor data compression with the extrapolation for real-time applications simultaneously.

关键词： Data compression interpolation and extrapolation phasor measurement unit real-time compression wide-area measurement system

来源：评论

学校读者我要写书评

暂无评论

interpolation and extrapolation Algorithm for Switching Events Compensation in Semi-Physical Simulation of Cascaded STATCOM

Interpolation and Extrapolation Algorithm for Switching Even...

引用

International Conference on Power System Technology (POWERCON)

作者： Lei, Ertao Ma, Ming Wang, Ling Liang, Xiaobing Yin, Xianggen Elect Power Res Inst Guangdong Power Grid Co Ltd Guangzhou Guangdong Peoples R China Huazhong Univ Sci & Technol Wuhan Hubei Peoples R China

ISBN: (纸本)9781538664612

To improve the accuracy of semi-physical simulation, this paper mainly discussed interpolation and extrapolation algorithms for switching events compensation of cascaded static synchronous compensators (STATCOM). The moment of the switching events was captured by Field-programmable gate array (FPGA). Two linear interpolations and one extrapolation were adopted to compensate the error caused by multiple switching events during one simulation step. In addition, a linear interpolation was also applied for time delay compensation in hardware in loop test. Both rapid control prototyping and hardware in loop tests were performed to verify the effectiveness of the interpolation algorithms. Experimental results indicated that the time delay was almost eliminated and the output waveform was improved after compensation.

关键词： STATCOM semi-physical simulation interpolation and extrapolation switching events compensation

来源：评论

学校读者我要写书评

暂无评论

Sidelobe Suppression for Random Stepped Frequency Signal Based on interpolation and extrapolation

Sidelobe Suppression for Random Stepped Frequency Signal Bas...

引用

International Conference on Radar Systems

作者： Liu Junhao Gao Liang Li Yinwei Wang Haitao Chen Qian Shanghai Radio Equipment Research Institute Shanghai China

ISBN: (纸本)9781785616723

For random stepped frequency radar (RSF) signal, the sidelobe level of high resolution range profile will fluctuate randomly due to the effects of discontinuous frequency spectra and frequencies hopping. The discrete Fourier transform (DFT) of interpolation and extrapolation (IE) is developed by the Bayesian criteria and minimizing the cost function, which is realized by iterative process. After the IE process, the phase of loss frequencies are extrapolated and recovered, and then the sidelobe of high range resolution profile (HRRP) is suppressed effectively at the same time. Finally the simulation analysis demonstrates that the developed method has better performance of sidelobe suppression in RSF radar.

关键词： Random stepped frequency interpolation and extrapolation Sidelobe suppression

来源：评论

学校读者我要写书评

暂无评论

Matrix-less spectral approximation for large structured matrices

引用

BIT NUMERICAL MATHEMATICS 2025年第1期65卷 1-35页

作者： Barbarino, Giovanni Claesson, Melker Ekstroem, Sven-Erik Garoni, Carlo Meadon, David Speleers, Hendrik Univ Mons Math & Operat Res Unit Mons Belgium Uppsala Univ Dept Informat Technol Uppsala Sweden Univ Roma Tor Vergata Dept Math Rome Italy

Sequences of structured matrices of increasing size, such as generalized locally Toeplitz sequences, arise in many scientific applications and especially in the numerical discretization of linear differential problems. We assume that the eigenvalues of a matrix Xn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X_n$$\end{document}, belonging to a sequence of such kind, are given by a regular expansion. Under this working hypothesis, we propose a method for computing approximations of the eigenvalues of Xn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X_n$$\end{document} for large n and we provide a theoretical analysis of its convergence. The method is called matrix-less because it does not operate on the matrix Xn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$X_n$$\end{document} but on a few similar matrices of smaller size combined with an interpolation-extrapolation strategy. The working hypothesis and the performance of the proposed eigenvalue approximation method are benchmarked on several numerical examples, with a special attention to matrices arising from the discretization of variable-coefficient differential problems.

关键词： Spectral approximation Structured matrices Discretization matrices Generalized locally Toeplitz sequences Eigenvalue expansion interpolation and extrapolation

来源：评论

学校读者我要写书评

暂无评论

A novel dual-stage grey-box stacking method for significantly improving the extrapolation performance of ship fuel consumption prediction models

引用

ENERGY 2025年 318卷

作者： Ruan, Zhang Huang, Lianzhong Li, Daize Ma, Ranqi Wang, Kai Zhang, Rui Zhao, Haoyang Wu, Jianyi Li, Xiaowu Dalian Maritime Univ Marine Engn Coll Dalian 116026 Liaoning Peoples R China China Merchants Energy Shipping Co Ltd Shenzhen 518067 Guangdong Peoples R China

Ship Fuel Consumption Prediction (SFCP) is the foundation of ship energy efficiency assessment and optimization. However, existing research neglects to examine the model extrapolation performance, leading to significant degradation in predictive accuracy when models face dataset shift. To address this, a novel dual-stage grey-box stacking (DSGBS) model is proposed. First, based on the traditional grey-box model (GBM), a light grey-box model (LGBM) is proposed to enhance the extrapolation ability by incorporating more prior knowledge. Then, an improved stacking framework is used to fuse multiple GBMs to build the DSGBS model. Finally, a physics- based white-box model (WBM) is established, along with black-box model (BBM), traditional GBM, and LGBM based on nine machine learning algorithms. The extrapolation performance of these models is compared using data from three independent voyages. Results show that DSGBS model has a significant advantage in extrapolation performance, reducing its RMSE by about 63.51 %, 10.91 %, and 52.52 %, respectively, compared to the best model in BBMs, the best model among GBMs and LGBMs, and WBM. Therefore, the DSGBS model mitigates prediction accuracy loss from dataset shift, significantly improve the extrapolation performance, and support the practical application of ship energy efficiency management, with great significance for reducing operation cost and emission.

关键词： Ship fuel consumption prediction Dataset shift Grey-box model interpolation and extrapolation Stacking

来源：评论

学校读者我要写书评

暂无评论

interpolation and extrapolation Method to Analyze Irradiation-Induced Dimensional Change Data of Graphite for Design of Core Components in Very High Temperature Reactor (VHTR)

引用

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY 2010年第7期47卷 591-598页

作者： Shibata, Taiju Kunimoto, Eiji Eto, Motokuni Shiozawa, Shusaku Sawa, Kazuhiro Oku, Tatsuo Maruyama, Tadashi Japan Atom Energy Agcy Oarai Ibaraki 3111393 Japan Toyo Tanso Co Ltd Mitoya Kagawa 7691102 Japan Ibaraki Univ Ibaraki Japan Tokyo Inst Technol Meguro Ku Tokyo 1528550 Japan

Graphite materials are used as core components in the High-Temperature Gas-Cooled Reactor (HTGR) and Very High Temperature Reactor (VHTR). The authors prepared technical documents for design, material, products, in-service inspection and maintenance of the graphite components for the HTGR/VHTR, which were summarized as a draft of standard for the graphite components through discussion made in a "Special committee on research on preparation for codes for graphite components in HTGR" set up within AESJ. The draft of standard contains graphical expressions for the irradiated material properties of IG-110 graphite. It is possible to use the graphical expressions for the components design of VHTR. The graphs were obtained based on the interpolation and extrapolation of the irradiation data. The irradiation-induced dimensional change of IG-110 graphite was obtained through the interpolation and extrapolation of the irradiation data with a quadratic equation of fast neutron fluence. The irradiation data for H-451 and ATR-2E graphites were used for the evaluation of the interpolation and extrapolation of irradiation data for IG-110. It was shown in this study that the proposed interpolation and extrapolation method is reasonable for IG-110 with regard to the database available at present.

关键词： HTGR VHTR IG-110 graphite irradiation-induced dimensional change interpolation and extrapolation component design standard

来源：评论

学校读者我要写书评

暂无评论

An experimental comparative study of the efficiency of twisted and flat flapping wings during hovering flight

引用

BIOINSPIRATION & BIOMIMETICS 2017年第3期12卷 036009-036009页

作者： Hoang Vu Phan Quang Tri Truong Park, Hoon Cheol Konkuk Univ Artificial Muscle Res Ctr Seoul South Korea Konkuk Univ Dept Adv Technol Fus Seoul South Korea Ho Chi Minh City Univ Technol & Educ Fac Mech Engn Ho Chi Minh Vietnam

This work presents a parametric study to find a proper wing configuration for achieving economical flight using unsteady blade element theory, which is based on the 3D kinematics of a flapping wing. Power loading was first considered as a performance parameter for the study. The power loadings at each wing section along the wingspan were obtained for various geometric angles of attack (AoAs) by calculating the ratios of the vertical forces generated and the power consumed by that particular wing section. The results revealed that the power loading of a negatively twisted wing could be higher than the power loading that a flat wing can have;the power loading of the negatively twisted wing was approximately 5.9% higher. Given the relatively low average geometric AoA (alpha(A),(root) approximate to 44 degrees and alpha(A),(tip) approximate to 25 degrees), the vertical force produced by the twisted wing for the highest power loading was approximately 24.4% less than that produced by the twisted wing for the strongest vertical force. Therefore, for a given wing geometry and flapping amplitude, a flapping-wing micro air vehicle required a 13.5% increase in flapping frequency to generate the same strongest cycle-average vertical force while saving about 24.3% power. However, when force(3)/power(2) and force(2)/power ratios were considered as performance indices, the twisted wings for the highest force(3)/power(2) (alpha(A),(root) approximate to 43 degrees and alpha(A),(tip) approximate to 30 degrees) and force(2)/power (alpha(A),(root) approximate to 43 degrees and alpha(A,tip) approximate to 36 degrees) required only 6.5% and 4% increases in flapping frequency and consumed 26.2% and 25.3% less power, respectively. Thus, it is preferable to use a flapping wing operating at a high frequency using the geometric AoAs for the highest power loading, force(3)/power(2) ratio, and force(2)/power ratio over a flapping wing operating at a low frequency using a high geometric AoA wit

关键词： flapping-wing MAV insect flight power loading wing kinematics twisted wing flat wing interpolation and extrapolation

来源：评论

学校读者我要写书评

暂无评论

Study on the Time Variability of Load Characteristics based on Markov Chain Monte Carlo Simulation 5

Study on the Time Variability of Load Characteristics based ...

引用

5th International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT)

作者： Zhou, Guangyao Wang, Zhenshu Wang, Xueli Shandong Univ Sch Elect Engn Jinan Peoples R China State Grid Shandong Elect Power Maintenance Co Jinan Peoples R China

ISBN: (纸本)9781467371063

The accurate degree of the load model in the whole time period has important influence on the decision of the system and the stability of the system. But the load is time-varying. Current algorithms can identify the load model with certain accuracy at the time points when the voltage is instable. In the moment with stable voltage, due to the difficulty of identifying the load model, they use a constant load model. This paper tries to find out the regularity of the time variation and solve the problem of the uncertainty of the load, and then put forward the corresponding method.

关键词： interpolation and extrapolation Markov Chain Monte Carlo simulation (MCMC) maximum likelihood PSO the tune-variance and the uncertainty of the load

来源：评论

学校读者我要写书评

暂无评论

Support vector machine based optimization of multi-fault classification of gears with evolutionary algorithms from time-frequency vibration data

引用

MEASUREMENT 2014年 55卷 1-14页

作者： Bordoloi, D. J. Tiwari, Rajiv Indian Inst Technol Guwahati Dept Mech Engn Gauhati 781039 India

A multi-fault classification of gears has been attempted by support vector machine (SVM) learning techniques with the help of time-frequency (wavelet) vibration data. A suitable exploitation of SVM is based on the selection of SVM parameters. The main focus of the present paper is to study the performance of the multiclass capability of SVM techniques. Different optimization methods (i.e., the grid-search method (GSM), the genetic algorithm (GA) and the artificial bee colony algorithm (ABCA)) have been performed for optimizing SVM parameters. Four fault conditions of gears have been considered. The continuous wavelet transform (CWT) and wavelet packet transform (WPT) are estimated from time domain signals, and a set of statistical features are extracted from the wavelet transform. The prediction of fault classification has been attempted at the same angular speed as the measured data as well as innovatively at the intermediate and extrapolated angular speed conditions, since it is not feasible to have measurement of vibration data at continuous speeds of interest. The classification ability is noted and compared with predictions when purely time domain data is used, and it shows an excellent prediction performance. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Support vector machine Optimization Multi-fault classification Wavelets interpolation and extrapolation

来源：评论

学校读者我要写书评

暂无评论

Optimum multi-fault classification of gears with integration of evolutionary and SVM algorithms

引用

MECHANISM AND MACHINE THEORY 2014年 73卷 49-60页

作者： Bordoloi, D. J. Tiwari, Rajiv Indian Inst Technol Guwahati Dept Mech Engn Gauhati 781039 India

In the present work, the multi-fault classification of gears has been attempted by the support vector machine (SVM) learning technique using frequency domain data. The proper utilization of SVM is based on the selection of SVM training parameters. The main focus of the paper is to examine the performance of the multiclass ability of SVM technique by optimizing its parameters using the grid-search method, the genetic algorithm(GA) and the artificial-bee-colony algorithm (ABCA). Four different fault conditions have been considered. Statistical features are extracted from frequency domain data. The prediction of fault classification has been attempted at the same angular speed as the measured data as well as innovatively at the intermediate and extrapolated angular speed conditions. This is important since it is not feasible to have measurement of data at all speeds of interest. The classification ability is noted and it demonstrates the excellent performance. (C) 2013 Elsevier Ltd. All rights reserved.

关键词： Support vector machine Optimization Multi-fault classification interpolation and extrapolation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：