检索结果-内蒙古大学图书馆

Hierarchically Distributed Optimization with a Flexible and Complexity-Reducing Algorithm

Journal of systems Science & Complexity 2024年第6期37卷 2530-2555页

作者： LIANG Shu ZHANG Lei WEI Yiheng LIU Yemo Department of Control Science and Engineering Tongji UniversityShanghai 200092China Shanghai Research Institute for Intelligent Autonomous Systems Shanghai 200092China School of Mathematics Southeast UniversityNanjing 211189China Beijing Aerospace Automatic Control Institute Beijing 100854China

In this paper,the authors consider distributed convex optimization over hierarchical *** authors exploit the hierarchical architecture to design specialized distributed algorithms so that the complexity can be reduced compared with that of non-hierarchically distributed *** this end,the authors use local agents to process local functions in the same manner as other distributed algorithms that take advantage of multiple agents'computing ***,the authors use pseudocenters to directly integrate lower-level agents'computation results in each iteration step and then share the outcomes through the higher-level network formed by *** authors prove that the complexity of the proposed algorithm exponentially decreases with respect to the total number of *** support the proposed decomposition-composition method for agents and pseudocenters,the authors develop a class of *** operators are generalizations of the widely-used subgradient based operator and the proximal operator and can be used in distributed convex ***,these operators are closed with respect to the addition and composition operations;thus,they are suitable to guide hierarchically distributed design and ***,these operators make the algorithm flexible since agents with different local functions can adopt suitable operators to simplify their ***,numerical examples also illustrate the effectiveness of the method.

关键词： Complexity convergence convex optimization distributed algorithm hierarchical network

来源：评论

学校读者我要写书评

暂无评论

Ensuring Correct Relay Protection Functioning in Transient Modes With Saturation of Current Transformers 7

Ensuring Correct Relay Protection Functioning in Transient M...

引用

7th International Scientific and Technical Conference Relay Protection and Automation, RPA 2024

作者： Panashchatenko, A.V. Yablokov, A.A. Department of Electric Power Systems Automatic Control Ivanovo State Power Engineering University Ivanovo Russia

ISBN: (纸本)9798331501105

Electromagnetic current transformers, invented more than 100 years ago, are today the most widespread type of preliminary current converters, used in organizing metrological channels for commercial and technical electricity metering, measuring and relay protection systems. Despite their relatively simple design and modest price, today the question of using unconventional preliminary current converters (Rogowski coils, optical transformers, galvanic-magnetic sensors) is being increasingly raised [1]. This situation is due to the shortcomings of electromagnetic current transformers (CT): large weight and dimensions), explosion and fire hazard, and also saturation of their magnetic conductor in transient modes with the presence of an aperiodic component in short circuiting (SC) current. The phenomenon of saturation leads to significant distortion of the transmitted secondary signal, which in turn may become the cause of overprotection with external SC or delayed protection with internal SC. Russian and international practice in coordinating CT characteristics and relay protection requirements presuppose ensuring correct operation of relay protection systems not only in steady, but also in transient modes with possible saturation of CT magnetic conductors [2]-[5]. At present, testing the correct operation of relay protection and automation devices (RPAD) in transient modes is carried out using the CT saturation time, which under the specific conditions of the location of the CT should be more than the exact current conversion time required for correct operation of the connected RPAD. This time is calculated by special approved methods [2]. Such use of two extreme CT magnetic conductor conditions (saturated/unsaturated), without regard to the current waveform itself may lead to significant inaccuracies in evaluating the correctness of RPAD operation. Fig 1 shows two instances of saturation in one and the same CT in different operating conditions and with the same time be

关键词： Relay protection

来源：评论

学校读者我要写书评

暂无评论

Assessment of the Digital Measuring Transformers Application in Power Distribution Zone

Assessment of the Digital Measuring Transformers Application...

引用

2024 International Russian Automation Conference, RusAutoCon 2024

作者： Filatova, Galina Lebedev, Vladimir Tolstoukhov, Andrey Ivanovo State Power Engineering University Automatic control of electric power systems department Ivanovo Russia

Combined digital measuring current and voltage transformers (DCVTs), developed at Ivanovo State Power engineering University (ISPEU), are innovative products. The researchers have accumulated some operating experience of devices in existing electrical installations and experience in numerous laboratory tests. At the same time, a number of aspects of the DCVT use still remain the subject of research, for example, the functioning of DCVTs as a primary sensor for protection against single-phase ground faults (SPGFs). It is also necessary to evaluate the effect of the introduction of DCVTs in the overhead networks of power distribution zones (PDZs), primarily from the point of view of reducing the costs of searching for the location of the SPGFs. The procedure for searching for an electrical fault using the functions built into DCVT 6 -10 kV is described. The article describes the effects of the introduction of DCVTs in 6-10 kV distribution zones, and also provides criteria that allow us to assess in which cases the use of DCVTs and technologies based on them will be most beneficial. © 2024 IEEE.

关键词： Distribution transformers

来源：评论

学校读者我要写书评

暂无评论

Processing Signals in Digital Current Measuring Transformers to Quickly Obtain the Vector for RPA Purposes

Processing Signals in Digital Current Measuring Transformers...

引用

2024 International Conference on Industrial engineering, Applications and Manufacturing, ICIEAM 2024

作者： Lebedev, Vladimir D. Grigorev, Denis G. Kuzmina, Nataliya V. Ivanovo State Power Engineering University Department Of Electric Power Systems Automatic Control Ivanovo Russia

ISBN: (纸本)9798350395013

In the development of secondary systems of stations and substations, including relay protection, automation, control, electric power metering and other features, there have recently been qualitative changes related to the introduction of digital technologies. The introduction of digital technologies is supported by innovative development programmes such as «Digital Transformation 2030». The essence of introducing digital technologies is related to the use of digital data transmission channels according to common standards. 'Digital substation' projects are being actively implemented with transmission of digital information at all levels, starting with primary equipment, including transmission of information, both from current and voltage measuring transformers, and switchgear. Currently, digital measuring transformers are being actively developed and beginning to be introduced, in which information on measured current and voltage is presented in a digital code. New approaches to measuring primary current and voltage, and the transmission of information pose new challenges and open up new prospects of improving signals processing methods used for relay protection purposes. This determines the relevance of the objective of our research - developing and studying approaches to the digital processing of signals in digital current and voltage measuring transformers. As a result, the approach to determining synchronized values of current vectors was studied by processing information obtained from primary current converters. The characteristics of the algorithm for obtaining the vector were analyzed, and the dependences of errors on the influence of distorting factors were plotted. The proposed approach to obtaining the vector is a development of the existing approach by obtaining information from current sensors operating on different physical principles. The study shows the advantages of the proposed method. © 2024 IEEE.

关键词： Relay protection

来源：评论

学校读者我要写书评

暂无评论

A low voltage ride through (LVRT) strategy using an active superconductor fault current limiter (SFCL) for a virtual synchronous generator (VSG) connected to a weak grid

A low voltage ride through (LVRT) strategy using an active s...

引用

2023 IEEE PES Innovative Smart Grid Technologies Europe, ISGT EUROPE 2023

作者： Kisinga, Daniel Angelo Trodden, Paul Department of Automatic Control and Systems Engineering University of Sheffield Sheffield United Kingdom

ISBN: (纸本)9798350396782

A function of grid-connected VSGs is facilitating the recovery of sagging voltages to nominal levels, achieved by supplying reactive power (Q) to the grid. During normal operation, however, a VSG is required to supply active power (P) at unity power factor and, therefore, in order to supply the Q required in the event of a sagging voltage, the VSG must change its control mode from P-supply to PQ- or Q-supply. Such transitions may induce high current flows—caused by the sudden reduction of the voltage during the sag—which are potentially damaging to the power semiconductor devices of the VSG;if these effects are to be avoided, the supplied current must be limited to its rated value, but this may result in a low power transfer from the VSG to the grid. To circumvent these problems, in this paper we propose a LVRT strategy using an active SFCL. We show that the proposed strategy, which combines a PQ decoupling scheme with an active SFCL, ensures maximum power transfer with an improved transient response during LVRT. © 2023 IEEE.

关键词： active SFCL LVRT PQ control voltage sag VSG

来源：评论

学校读者我要写书评

暂无评论

Reinforcement Learning for Multiple-Input Multiple-Output control in Metal Additive Manufacturing 20

Reinforcement Learning for Multiple-Input Multiple-Output Co...

引用

20th IEEE International Conference on Networking, Sensing and control, ICNSC 2023

作者： Grais, Emad M. Notley, Scott V. Panoutsos, George University of Sheffield Department of Automatic Control and Systems Engineering Sheffield United Kingdom

ISBN: (纸本)9798350369502

In laser powder bed fusion additive manufacturing, using fixed values for the process parameters (beam power, velocity, and other parameters) may not lead to homogeneously distributed heat in all locations in the build, especially around complex design features. This could lead to builds with defects, leading to poor mechanical and micro-structure properties. To guarantee heat homogeneity, the process parameters need to be actively controlled to adapt to different locations in the build. Builds with varying geometrical features would need different control strategies. In this work, we propose to use reinforcement learning (RL) to control, for the first time, simultaneously multiple AM process parameters to achieve consistent melting properties. Our results show that using RL as a multiple-input multiple-output control system achieves a more consistent meltpool geometry. © 2023 IEEE.

关键词： Reinforcement learning

来源：评论

学校读者我要写书评

暂无评论

Nonlinear Identification for control by Using HARMAX Models 9

Nonlinear Identification for Control by Using HARMAX Models

引用

9th International Conference on control, Decision and Information Technologies, CoDIT 2023

作者： Culita, Janetta Stefanoiu, Dan Nica, Andreea-Maria University 'Politehnica' of Bucharest Department of Automatic Control and Systems Engineering Romania University 'Politehnica' of Bucharest Faculty of Automatic Control and Computers Romania

ISBN: (纸本)9798350311402

The purpose of this article is to perform a comparison between two identification models: a nonlinear one referred to as HARMAX and a classical linear one, of Box-Jenkins (BJ) type. The first model modifies a classical ARMAX model by applying Hammerstein polynomials on input, output, and noise signals. Identification of models was performed by means of Multi-Step Least Squares Method, as described into the article. The simulations on a real-world plant, namely ASTANK2, a fluidic system with two inputs, two outputs and nonlinear static characteristic, have proven that the HARMAX model performs better than the BJ model and provides more accurate useful models to be integrated into closed loop configurations. © 2023 IEEE.

关键词： Optimization

来源：评论

学校读者我要写书评

暂无评论

On Sparse Nonlinear System Identification Using Orthogonal Matching Pursuit, Orthogonal Least Squares and LASSO 32

On Sparse Nonlinear System Identification Using Orthogonal M...

引用

32nd Mediterranean Conference on control and Automation, MED 2024

作者： Wei, Hua-Liang The University of Sheffield The Department of Automatic Control and Systems Engineering SheffieldSI 3JD United Kingdom

ISBN: (纸本)9798350395440

System identification, as a rich and vital discipline, provides a practical and general methodology and tool for quantitatively modelling the input-output relationships of dynamical systems. Sparse nonlinear system identification (SNSI), especially parametric sparse nonlinear system identification (PSNSI), is an important and vital field of research with a wide range of applications. This work is concerned with PSNSI and particular attention is paid to the assessment of three well-known mainstream sparse learning methods, namely, orthogonal least squares (OLS), orthogonal matching pursuit (OMP) and least absolute shrinkage and selection operator (LASSO). The performances of these methods are tested and evaluated through three case studies relating to PSNSI problems. The research results and findings of this work provide practical useful information and guidance for researchers to better choose or adapt methods when solving PSNSI problems. © 2024 IEEE.

关键词： Dynamical systems

来源：评论

学校读者我要写书评

暂无评论

Analysis of the Findings of the Study of the Time to Saturation of Current Transformer Magnetic Circuits Located at Electric Power Facilities

Analysis of the Findings of the Study of the Time to Saturat...

引用

2024 International Ural Conference on Electrical Power engineering, UralCon 2024

作者： Yablokov, Andrey Panashchatenko, Anton Ivanovo State Power Engineering University ISPU Department of Electric Power Systems Automatic Control Ivanovo Russia

ISBN: (纸本)9798350386028

Emergencies associated with incorrect operation of relay protection and automation (RPA) devices due to saturation of current transformers (CTs) can lead to great economic damage. The article presents an analysis of regulatory and technical documentation containing requirements for the quality of CT functioning in transient modes, statistical data on the results of calculations performed in accordance with the requirements of GOST R 58869-2019, as well as an analysis of the correctness of the assumptions introduced by it. To calculate the time to CTs saturation a special program was developed that automates the calculation methods, taking into account the assumptions focused on performing the manual calculations. The program takes into account the variation of the short circuit switching angle, the phase difference of the short circuit currents flowing through the branches feeding the short circuit point, the calculation of all CTs of a three-phase group with automatic selection of the worst result. The results obtained allow us to conclude about the relative number of CTs that do not meet the requirements of GOST R 58869-2019, the need to modernize existing methods and possible directions for such modernization. In addition, the article provides recommendations on the creation of automatic specialized software systems that can be used in the work of design, operating and research entities when they calculate the time to saturation of the CT magnetic circuits. © 2024 IEEE.

关键词： Transformer protection

来源：评论

学校读者我要写书评

暂无评论

Robotic Assembly of Aviation Fuel Probes and Parameters Optimisation Using Bees Algorithm 25

Robotic Assembly of Aviation Fuel Probes and Parameters Opti...

引用

25th IEEE International Conference on Industrial Technology, ICIT 2024

作者： Lin, Xiaoguo Qu, Mo Noguera, Marc Auledas Tiwari, Ashutosh Wang, Yongjing University Of Birmingham Department Of Mechanical Engineering Birmingham United Kingdom University Of Sheffield Department Of Automatic Control And Systems Engineering Sheffield United Kingdom

ISBN: (纸本)9798350340266

Robots for automated assembly are being progressively implemented in the aerospace manufacturing sector. The dim and complex internal structure of the aircrafts significantly complicates the operation of robotic arms through visual system. This paper proposes an assembly strategy based on force-feedback control for fuel probe installation inside the aircraft wings, enabling autonomous assembly of tubular objects under translational and rotational misalignments. Furthermore, the Bees Algorithm (BA) is employed in a simulation environment to optimise the parameters of this control strategy. The results demonstrate that BA can effectively decrease the overall installation time while simultaneously proving the effectiveness of this method and its potential applicability in aerospace manufacturing. © 2024 IEEE.

关键词： Probes

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：