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Monolithic integrated optoelectronic chip for vector force detection

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Microsystems & Nanoengineering 2024年第3期10卷 245-257页

作者： Jiansong Feng Zhongqi Wang Mengyuan Zhanghu Xu Zhang Yong Shen Jing Yang Zhibin Li Bin Chen Taihong Wang Xiaolong Chen Zhaojun Liu department of electrical and electronic engineering Southern University of Science and TechnologyShenzhen 518055China department of electrical and electronic engineering The University of Hong KongHong KongChina

Sensors with a small footprint and real-time detection capabilities are crucial in robotic surgery and smart wearable *** device footprint while maintaining its high performance is a major challenge and a significant limitation to their ***,we proposed a monolithic integrated micro-scale sensor,which can be used for vector force *** sensor combines an optical source,four photodetectors,and a hemispherical silicone elastomer component on the same sapphire-based AlGaInP *** chip-scale optical coupling is achieved by employing the laser lift-off techniques and the flip-chip bonding to a processed sapphire *** hemispherical structure device can detect normal and shear forces as low as 1mN within a measurement range of 0–220 mN for normal force and 0–15 mN for shear *** packaging,the sensor is capable of detecting forces over a broader range,with measurement capabilities extending up to 10 N for normal forces and 0.2 N for shear *** has an accuracy of detecting a minimum normal force of 25 mN and a minimum shear force of 20 ***,this sensor has been validated to have a compact footprint of approximately 1.5 mm^(2),while maintaining high real-time *** also demonstrate its promising potential by combining this sensor with fine surface texture perception in the fields of compact medical robot interaction and wearable devices.

关键词： robot force smart

Communication Resources Allocation for Time Delay Reduction of Frequency Regulation Service in High Renewable Penetrated Power System

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CSEE Journal of Power and Energy systems 2024年第2期10卷 468-480页

作者： Hongjie He Ning Zhang Chongqing Kang Song Ci Fei Teng Goran Strbac State Key Laboratory of Power systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China department of electrical and electronic engineering Imperial College LondonSW72BULondonU.K

The high renewable penetrated power system has severe frequency regulation *** resources can provide frequency regulation services but are limited by com-munication time *** paper proposes a communication resources allocation model to reduce communication time delay in frequency regulation *** device resources and wireless spectrum resources are allocated to distributed resources when they participate in frequency *** reveal impact of communication resources allocation on time delay reduction and frequency regulation ***,we study communication resources allocation solution in high renewable energy penetrated power *** provide a case study based on the HRP-38 *** show communication time delay decreases distributed resources'ability to provide frequency regulation *** the other hand,allocating more communication resources to distributed resources'communica-tion services improves their frequency regulation *** power systems with renewable energy penetration above 70%,required communications resources are about five times as many as 30%renewable energy penetrated power systems to keep frequency performance the *** Terms-Communication resources allocation,commun-ication time delay,distributed resource,frequency regulation,high renewable energy penetrated power system.

关键词： Communication resources allocation communication time delay distributed resource frequency regulation high renewable energy penetrated power system

Empirical Wavelet Transform Based Method for Identification and Analysis of Sub-synchronous Oscillation Modes Using PMU Data

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Journal of Modern Power systems and Clean Energy 2024年第1期12卷 34-40页

作者： Joice G.Philip Jaesung Jung Ahmet Onen the department of Energy systems Research Ajou UniversitySuwonSouth Korea the department of electrical and electronic engineering Abdullah Gul UniversityKayseri38080Turkey the department of electrical and Computer engineering College of EngineeringSultan Qaboos UniversityAl-KhoudMuscatOman

This paper proposes an empirical wavelet transform(EWT)based method for identification and analysis of sub-synchronous oscillation(SSO)modes in the power system using phasor measurement unit(PMU)*** phasors from PMUs are preprocessed to check for the presence of *** the presence is established,the signal is decomposed using EWT and the parameters of the mono-components are estimated through Yoshida *** superiority of the proposed method is tested using test signals with known parameters and simulated using actual SSO signals from the Hami Power Grid in Northwest *** show the effectiveness of the proposed EWT-Yoshida method in detecting the SSO and estimating its parameters.

关键词： Empirical wavelet transform(EWT) sub-synchronous oscillation Prony-based method Yoshida algorithm variational mode decomposition phasor measurement unit(PMU)

Statistical analysis and interpretation on lightning impulse breakdown voltages of ester liquids under varying field uniformity

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High Voltage 2024年第1期9卷 22-34页

作者： Haichuan Yu Qiang Liu Zhongdong Wang department of electrical and electronic engineering The University of ManchesterManchesterUK department of engineering University of ExeterExeterUK

Ester liquids(ELs),as the alternative transformer liquids to the conventional mineral oils(MOs),have been increasingly used in power transformers with high voltage *** various properties,the lightning impulse breakdown voltages(LIBDVs)have been studied elaborately in the past two decades under different electric field *** electric field uniformities do have an effect on the breakdown characteristics,for example,breakdown mechanisms,polarity effects,and differences of LIBDV between ELs and MOs,which is quantitatively investigated based on the LIBDVs collected from the *** breakdown mechanism transition phenomenon between streamer initiation dominated breakdown and streamer propagation dominated breakdown has been reviewed ***,the transition field factor boundaries to observe the polarity effect on LIBDVs are taken at around 20 for ELs and 10 for ***,the transition field factor boundaries to observe the LIBDV distinctions between ELs and MOs are about 109 and 14 under positive and negative lightning impulse,*** systematic analysis and interpretation on the transition field factor boundaries among different phenomena can provide insights on insulation design of ELs filled power transformers.

关键词： field lightning breakdown

A Review of State-of-the-art Flexible Power Point Tracking Algorithms in Photovoltaic systems for Grid Support:Classification and Application

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Journal of Modern Power systems and Clean Energy 2024年第1期12卷 1-21页

作者： Mina Haghighat Mehdi Niroomand Hossein Dehghani Tafti Christopher D.Townsend Tyrone Fernando the department of electrical engineering University of IsfahanIsfahanIran the department of electrical Electronic and Computer EngineeringUniversity of Western AustraliaCrawley WA 6009Australia

To maximize conversion efficiency,photovoltaic(PV)systems generally operate in the maximum power point tracking(MPPT)***,due to the increasing penetra tion level of PV systems,there is a need for more developed control functions in terms of frequency support services and voltage control to maintain the reliability and stability of the power ***,flexible active power control is a manda tory task for grid-connected PV systems to meet part of the grid ***,a significant number of flexible pow er point tracking(FPPT)algorithms have been introduced in the existing *** purpose of such algorithms is to real ize a cost-effective method to provide grid support functional ities while minimizing the reliance on energy storage *** paper provides a comprehensive overview of grid support functionalities that can be obtained with the FPPT control of PV systems such as frequency support and volt-var *** of these grid support functionalities necessitates PV sys tems to operate under one of the three control strategies,which can be provided with FPPT *** three control strate gies are classified as:①constant power generation control(CP GC),②power reserve control(PRC),and③power ramp rate control(PRRC).A detailed discussion on available FPPT algo rithms for each control strategy is also *** paper can serve as a comprehensive review of the state-of-the-art FPPT algorithms that can equip PV systems with various grid support functionalities.

关键词： Maximum power point tracking(MPPT) flexi ble power point tracking(FPPT) power reserve control(PRC) power ramp rate control(PRRC) low voltage ride-through(LVRT) constant power generation(CPG)

An Improved Modulation Strategy for Single-phase Three-level Neutral-point-clamped Converter in Critical Conduction Mode

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Journal of Modern Power systems and Clean Energy 2024年第3期12卷 981-990页

作者： Ning Li Yujie Cao Xiaokang Liu Yan Zhang Ruotong Wang Lin Jiang Xiao-Ping Zhang School of electrical engineering Xi’an University of TechnologyXi’anChina the department of electronics Information and BioengineeringPolitecnico di MilanoMilanItaly Xi’an Jiaotong University Xi’anChina the department of electrical engineering and electronics University of LiverpoolLiverpoolU.K. the department of electronic Electrical and Systems EngineeringUniversity of BirminghamBirminghamU.K.

Two-level totem-pole power factor correction(PFC)converters in critical conduction mode(CRM)suffer from the wide regulation range of switching ***,in highfrequency applications,the number of switching times increases,resulting in significant switching *** solve these issues,this paper proposes an improved modulation strategy for the single-phase three-level neutral-point-clamped(NPC)converter in CRM with *** optimizing the discharging strategy and switching state sequence,the switching frequency and its variation range have been efficiently *** detailed performance analysis is also presented regarding the switching frequency,the average switching times,and the effect of voltage gain.A 2 k W prototype is built to verify the effectiveness of the proposed modulation strategy and analysis *** with the totem-pole PFC converter,the switching frequency regulation range of the three-level PFC converter is reduced by 36.48%and the average switching times is reduced by 45.10%.The experimental result also shows a 1.2%higher efficiency for the three-level PFC converter in the full load range.

关键词： Critical conduction mode(CRM) on-board charger switching frequency range switching times power factor correction(PFC) three-level converter

Performance Analysis of the Reconfigurable Intelligent Surfaces Communication systems

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Journal of Communications and Information Networks 2024年第2期9卷 184-191页

作者： Omar Abu Ella department of electrical and electronic engineering Misurata University2659 Zawiat AlmahjoubMisurataLibya

Reconfigurable intelligent surfaces (RIS) play a vital role in meeting the growing demand for higher data rates and reliability in wireless systems. This study focuses on analyzing the performance of RIS systems to gain a deeper understanding of their *** paper presents a mathematical analysis of the RIS system,deriving closed-form formulae that express its characteristics including signal-to-noise ratio(SNR)distribution,ergodic and effective capacity,outage,and error probability. The obtained formulae are newly derived and unconditionally valid solutions. Numerical results demonstrate a close agreement between the derived formulae and MonteCarlo simulation outcomes.

关键词： ergodic capacity effective capacity outage probability bit error rate Rayleigh fading channel RISassisted communication system

Optimal Offering of Energy Storage in UK Day-Ahead Energy and Frequency Response Markets

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Journal of Modern Power systems and Clean Energy 2024年第2期12卷 415-426页

作者： Makedon Karasavvidis Andreas Stratis Dimitrios Papadaskalopoulos Goran Strbac department of electrical and electronic engineering Imperial College LondonLondonUK Statkraft UK Ltd. LondonUK department of electrical and Computer engineering University of PatrasPatrasGreece IEEE

The offering strategy of energy storage in energy and frequency response(FR) markets needs to account for country-specific market regulations around FR products as well as FR utilization factors, which are highly uncertain. To this end, a novel optimal offering model is proposed for stand-alone price-taking storage participants, which accounts for recent FR market design developments in the UK, namely the trade of FR products in time blocks, and the mutual exclusivity among the multiple FR products. The model consists of a day-ahead stage, devising optimal offers under uncertainty, and a real-time stage, representing the storage operation after uncertainty is materialized. Furthermore, a concrete methodological framework is developed for comparing different approaches around the anticipation of uncertain FR utilization factors(deterministic one based on expected values, deterministic one based on worst-case values, stochastic one, and robust one), by providing four alternative formulations for the real-time stage of the proposed offering model, and carrying out an out-of-sample validation of the four model instances. Finally, case studies employing real data from UK energy and FR markets compare these four instances against achieved profits, FR delivery violations, and computational scalability.

关键词： Energy markets energy storage frequency response optimal offering robust optimization stochastic programming

Constructions of optimal binary locally repairable codes via intersection subspaces

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Science China(Information Sciences) 2024年第6期67卷 418-432页

作者： Wenqin ZHANG Deng TANG Chenhao YING Yuan LUO School of electronic Information and electrical engineering Shanghai Jiao Tong University

Locally repairable codes（LRCs）, which can recover any symbol of a codeword by reading only a small number of other symbols, have been widely used in real-world distributed storage systems, such as Microsoft Azure Storage and Ceph Storage Cluster. Since binary linear LRCs can significantly reduce coding and decoding complexity, constructions of binary LRCs are of particular interest. The aim of this paper is to construct dimensional optimal binary LRCs with disjoint local repair groups. We introduce a method to connect intersection subspaces with binary LRCs and construct dimensional optimal binary linear LRCs with locality 2b（b 3） and minimum distance d 6 by employing intersection subspaces deduced from the direct sum. This method will sufficiently increase the number of possible repair groups of dimensional optimal LRCs, thus efficiently expanding the range of the construction parameters while keeping the largest code rates compared with all known binary linear LRCs with minimum distance d 6 and locality 2b.

关键词： locally repairable codes disjoint local repair groups distributed storage systems intersection subspaces direct sum

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