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Cepstrum Lifting and Coherent Averaging-Based Instantaneous Frequency Estimation of Low-Amplitude Signal Components for Rotating Machinery

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IEEE Sensors Journal 2025年第10期25卷 17479-17490页

作者： Liu, Shaokang Liu, Shuai Wu, Yingjie Liu, Weiliang Liu, Changliang Luo, Zhihong North China Electric Power University Control and Computer Engineering Department Beijing102200 China Baoding Key Laboratory of State Detection and Optimization Regulation for Integrated Energy System Baoding071000 China Northeast Electric Power University Automation Engineering Department Jilin132000 China Inner Mongolia University of Technology Electric Power Department Hohhot010080 China

Instantaneous frequency (IF) serves multiple critical functions in the prognostic and health management of rotating machinery. The current IF estimation methodologies primarily concentrate on enhancing estimation accuracy at the algorithmic level. However, in practical industrial applications, the target signal component is often influenced by varying operating conditions, structural resonances, and background noise, causing it to become submerged or even disappear, ultimately resulting in the failure of conventional IF estimation techniques. To address these challenges, a novel IF estimation approach incorporating signal quality enhancement is developed. First, the complementary multisource vibration signal is processed by the proposed segmented cepstrum lifting (CL) method to overcome the submersion of the resonant frequency band on the target component. Then, the processed segmented signals are fused using coherent averaging (CA) technology to enhance the amplitude of the target component. Finally, leveraging the first-order approximation capability of the short-time fractional Fourier transform (STFrFT) for nonlinear frequency modulation modes, precise IF estimation is achieved. Verified by field data, the proposed method outperforms mainstream methods in both accuracy and applicability, highlighting its industrial application prospects. © 2001-2012 IEEE.

关键词： Frequency estimation

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Geometric Methods for Assessing the Value and Demands of Energy Storage in Power system Operation

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Energy Internet 2025年第1期2卷 86-103页

作者： Qi Lv Boshen Zheng Shengwei Mei Wei Wei Department of Electrical Engineering State Key Laboratory of Power System Operation and Control Tsinghua University Beijing China

Driven by the desire of a low-carbon society, the penetration level of renewable generation in the power grid of China will still grow fast in the near future. As the synchronised generators whose output is controllable are gradually replaced by volatile energy resources, energy storage is expected to play a vital role in regulation services and flexibility provision. Because the capital cost of energy storage is still relatively high, it is important to assess the value or demand of energy storage before making an investment decision. This paper presents two representative mathematical tools to achieve this target in a geometric fashion. The first one is the multi-parametric programming method. It depicts the reduced cost by deploying energy storage through post-optimal value function, which is easy to visualise or can be embedded in high-level optimisation problems such as storage sizing. The second one is a polyhedral projection method. It represents all feasible power-energy capacity pairs of a storage unit to achieve a certain target. The above methods remove the need of repeatedly solving a large number of problems with varying capacity parameters. Simple examples are given for illustration, and the presented methods can also directly handle problems with complex models and constraints.

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Small Signal Stability-Guaranteed Moving Target Defense Against Load Redistribution Attack On IoT-based Smart Grid

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IEEE Internet of Things Journal 2025年第11期12卷 17413-17429页

作者： Wang, Bingdong Zhang, Zhenyong Wang, Mufeng Liu, Mengxiang Ye, Rui Deng, Ruilong Zhang, Xin Guizhou University State Key Laboratory of Public Big Data College of Computer Science and Technology Guiyang550025 China China Industrial Control Systems Cyber Emergency Response Team Beijing100040 China University of Sheffield Department of Automatic Control and System Engineering Sheffield United Kingdom Guizhou Power Grid Co. Ltd. Intelligent Operation Center China Zhejiang University State Key Laboratory of Industrial Control Technology College of Control Science and Engineering Hangzhou310027 China Huzhou Institute of Industrial Control Technology Huzhou313000 China

Moving target defense (MTD) is a promising approach to defend against load redistribution attacks on the internet-of-things (IoT)-based smart grid networks by probing the distorted state estimates with the distributed flexible AC transmission system. However, existing studies mainly focus on optimizing the performance of MTD and ignore the safety effect of it on the system’s operation. In this paper, we fill this gap by deeply analyzing the effect of MTD on the small signal stability and aim to alleviate the negative impact and guarantee its defending performance simultaneously. Firstly, the stability is formally described using the eigenvalue sensitivity. The relationship between the MTD-induced perturbation (MTDper) and the stability criteria is derived. Secondly, a new indicator is proposed to measure the effectiveness of MTDper. Thirdly, a constrained optimization problem is formulated to compute the bound of MTDper for guaranteeing the small signal stability. In addition, a surprising finding is that the stability margin can be improved and enhanced by optimizing the value of MTDper without losing the MTD’s effectiveness. Finally, we evaluate the performance of MTDper and its impact on the small signal stability with extensive simulations on the IEEE 30-bus, 39-bus, and 68-bus test power systems. © 2014 IEEE.

关键词： Constrained optimization

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Semi-Autonomous Navigation Based on Local Semantic Map for Mobile Robot

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Journal of Shanghai Jiaotong university(Science) 2025年第1期30卷 27-33页

作者： ZHAO Yanfei XIAO Peng WANG Jingchuan GUO Rui Department of Automation Institute of Medical RoboticsShanghai Jiao Tong UniversityShanghai200240China State Key Laboratory of System Control and Information Processing Ministry of Education of ChinaShanghai200240China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai200240China State Grid Intelligence Technology Co. Ltd.Jinan250013China

Mobile robots represented by smart wheelchairs can assist elderly people with mobility *** paper proposes a multi-mode semi-autonomous navigation system based on a local semantic map for mobile robots,which can assist users to implement accurate navigation(e.g.,docking)in the environment without prior *** order to overcome the problem of repeated oscillations during the docking of traditional local path planning algorithms,this paper adopts a mode-switching method and uses feedback control to perform docking when approaching semantic *** last,comparative experiments were carried out in the real *** show that our method is superior in terms of safety,comfort and docking accuracy.

关键词： semi-autonomous navigation mobile robot semantic map voice interaction

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Advanced Grid-Forming Undersea Pumped Storage to Enable 100% Renewable Offshore Oilfield Power systems

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IEEE Transactions on Sustainable Energy 2025年

作者： Su, Kaiyuan Wang, Xi Xie, Xiaorong Tsinghua University State Key Laboratory of Power System Operation and Control Department of Electrical Engineering Beijing100084 China

To advance carbon reduction of the offshore oilfield power system (OOPS), the grid-forming undersea pumped storage system (GFM-UPSS) emerges as a promising solution. This paper introduces a novel framework for a 100% renewable OOPS utilizing the GFM-UPSS. Firstly, the control strategy of the GFM-UPSS is presented. It consists of the grid-side converter (GSC), machine-side converter (MSC), and reversible pump-turbine (RPT) to achieve frequency and voltage regulation. A steady-state model is then developed detailing the water head, power, and volume of the spherical shell. In addition, the paper explores the converter parameter impacts on the GFM-UPSS transient model and derives the closed-form solutions. With the steady-state model, an optimal sizing method is presented and economic advantages in the marine environment are studied for the GFM-UPSS. Finally, EMT simulations are conducted to assess the frequency & voltage stabilities and verify the effectiveness of the GFM-UPSS in enabling a 100% renewable OOPS. The optimal sizing results show that construction costs, mainly for OWP, are dominated and are influenced by sphere radius, placement depth, and start-stop cycles, while a 2.5 capacity ratio between OWP and GFM-UPSS consistently emerges as optimal. Moreover, analysis of transient stability shows that it improves with higher frequency & voltage modulation coefficient and lower virtual impedance. The impact of RPT and MSC, mainly on frequency regulation, is determined by the DC droop coefficient and turbine inertia. © 2010-2012 IEEE.

关键词： Offshore oil fields

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Numerical Simulation of Streamer Discharge in Transformer Oil Under Various Ionization Energies 19th

Numerical Simulation of Streamer Discharge in Transformer Oi...

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19th Annual Conference of China Electrotechnical Society, ACCES 2024

作者： Bao, Yanyan Liang, Shaobin Wang, Feng Zhang, Guangdong Chen, Jianning Zhou, Yuanxiang State Grid Gansu Electric Power Research Institute Lanzhou730070 China State Key Laboratory of Power System Operation and Control Beijing100084 China Department of Electrical Engineering Tsinghua University Beijing100084 China

ISBN: (纸本)9789819613786

Discharge in transformer oil is one of the primary causes of transformer failures. The physical mechanisms of oil discharges are not yet fully understood. Scholars have simulated the discharge process with electrodynamics model, but there is limited research on how the ionization energy, which changes due to various factors such as components and temperature of transformer oil, affect the streamer discharge characteristic. To improve the mechanism of discharge in transformer oil, this paper adopts an electrohydrodynamic model to study the impact of different ionization energies on the streamer discharge characteristics of transformer oil, including initiation voltage, discharge voltage, development speed, and electric field strength. When the ionization energy is between 6.1 eV and 8.1 eV, the initiation voltage and discharge voltage increase linearly with the ionization energy. Within the range of 7.1 eV to 8.1 eV, the time in the streamer accumulation phase increases exponentially with the ionization energy, while the streamer development speed decreases. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Electrohydrodynamics

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Streamlining the New Product Introduction by Integrating the Escalation Process 18th

Streamlining the New Product Introduction by Integrating the...

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18th International Conference on Interdisciplinarity in engineering, INTER-ENG 2024

作者： Zgirdea, Mihai Ionica, Andreea Cristina Leba, Monica Engineering and Management Doctoral School University of Petrosani 20 Universitatii Petrosani332006 Romania Management and Industrial Engineering Department University of Petrosani 20 Universitatii Petrosani332006 Romania Computer and System Control Engineering Department University of Petrosani 20 Universitatii Petrosani332006 Romania

ISBN: (纸本)9783031813771

In the dynamic landscape of modern business, companies face the challenge of rapidly introducing new products to meet consumer demands. This research aims to propel NPI efficiency, focusing on the automotive industry, by enhancing cooperative effectiveness and streamlining processes. The overarch- ing objective is to expedite high-quality product with the focus of introducing a controlled escalation process to facilitate swift corrections and improvements throughout each phase of NPI. To realize these objectives, a comprehensive NPI system has been developed. Integration of an escalation process into this sys- tem enables hierarchical escalation of concerns, blocking points, and new pro- cesses, addressing common project delays. The proposed software stands out for its unique integration of the escalation process, ensuring that all organizational members are promptly informed of any deviations using a dynamic project status feature, adapting as the project progresses. The integrated escalation process not only addresses anomalies promptly but also quantifies the time taken to restore normalcy or implement corrections, thereby fostering a more responsive and effi- cient NPI framework. The paper is organized into sections comprising a literature review on NPI methodologies, the integration of an escalation process into the NPI framework, a case study illustrating the implementation of the escalation process in an existing NPI methodology, and the subsequent results. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： Automotive Industry Collaborative Teamwork controlled Escalation Process Dynamic NPI Software New Product Introduction (NPI)

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Architecture of AC-DC Energy Nodes in Supergrids: A Technical Foundation for Future Renewable Integration

Architecture of AC-DC Energy Nodes in Supergrids: A Technica...

引用

Applied Research in Electrical engineering (AREE), National and International Conference on

作者： Mohammad Hossein Mousavi Hassan Moradi Kumars Rouzbehi Department of Computer and Electrical Engineering Razi University Kermanshah Iran Department of System Engineering and Automatic Control University of Seville Seville Spain

ISBN: (数字)9798350377170

ISBN: (纸本)9798350377187

The AC-DC Energy Nodes (ADENs) concept offers a transformative approach to modernizing power grids, particularly in the context of supergrids. By centralizing power flows from diverse renewable energy sources, such as offshore wind farms, ADENs enable efficient long-distance power transmission through HVDC technology. This design enhances the balance of supply and demand across regions and countries, significantly improving grid stability and resilience. However, the implementation of ADENs presents substantial technical, regulatory, and cybersecurity challenges. This study delves into these challenges while also addressing the geopolitical complexities of transnational connections, underscoring the critical importance of policy alignment for successful deployment.

关键词： Renewable energy sources Supply and demand Protocols HVDC transmission Wind farms Power system stability Stability analysis Computer security Protection Resilience

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Coordinate projected gradient descent minimization and its application to orthogonal nonnegative matrix factorization

arXiv

引用

arXiv 2025年

作者： Chorobura, Flavia Lupu, Daniela Necoara, Ion Automatic Control and System Engineering Department University Politehnica Bucharest Spl. Independentei Bucharest060042 Romania

In this paper we consider large-scale composite nonconvex optimization problems having the objective function formed as a sum of three terms, first has block coordinate-wise Lipschitz continuous gradient, second is twice differentiable but nonseparable and third is the indicator function of some separable closed convex set. Under these general settings we derive and analyze a new cyclic coordinate descent method, which uses the partial gradient of the differentiable part of the objective, yielding a coordinate gradient descent scheme with a novel adaptive stepsize rule. We prove that this stepsize rule makes the coordinate gradient scheme a descent method, provided that additional assumptions hold for the second term in the objective function. We also present a worst-case complexity analysis for this new method in the nonconvex settings. Numerical results on orthogonal nonnegative matrix factorization problem also confirm the efficiency of our algorithm. © 2025, CC BY.

关键词： Matrix algebra

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Broadband Optical Nonlinearities and Ultrafast Carrier Dynamics of GO-CuS Hybrid Film

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Journal of Lightwave Technology 2025年第11期43卷 5381-5389页

作者： Zhang, Xuefeng Bai, Xuli Liu, Xiaofei Wang, Dan Han, Hong Xiao, Zhengguo Zhang, Jianguo Nie, Zhongquan Taiyuan University of Technology College of Materials Science and Engineering Institute of New Carbon Materials Taiyuan030024 China Taiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Electronic Information and Optical Engineering Taiyuan030024 China Taiyuan Institute of Technology Department of Science Taiyuan030008 China Tongren University Department of Physics and Electronic Engineering Tongren China National University of Defense Technology College of Advanced Interdisciplinary Studies Changsha410073 China

We report the broadband optical nonlinearities and ultrafast carrier dynamics of GO doped with CuS nanoparticles (GO-CuS) following the femtosecond pulse lasers. Both the pure GO and GO-CuS hybrid films are first synthesized by the vacuum filter deposition method and their optical nonlinearities are then examined in the wide wavelength range (400 nm-1064 nm) based on the femtosecond Z-scan technique. The results reveal that, compared to the pristine GO, the introduction of CuS not only makes the GO-CuS hybrid film switched from saturated absorption to reverse saturated absorption possible, but also achieves strong broadband optical nonlinear absorption responses and optical limiting effects. It is demonstrated that the strongest nonlinear absorption coefficient (∼3.6×10-7 m/W) appears at 400 nm excitation, which is dozens of times larger than that under the illumination of 1064 nm. By leveraging the femtosecond pump-probe technique, we further study the ultrafast carrier dynamics of the GO-CuS hybrid film carrying the fast and slow relaxation processes. Moreover, the physical mechanisms behind these excellent nonlinear optical responses are elucidated. The findings presented here indicate that the GO-CuS hybrid film can be regarded as a potential promising candidate in various ultrafast photonics devices. © 1983-2012 IEEE.

关键词： Femtosecond lasers

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