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High Voltage 2024年第2期9卷 296-308页

作者： Lijun Yang Zhidong Cheng Li Cheng Ruijin Liao state key laboratory of power transmission equipment technology School of Electrical EngineeringChongqing UniversityChongqingChina

Because DC conductivities of oil-paper materials can be easily affected by electric field and temperature,the electrical properties under electro-thermal coupling of oil-paper materials should be considered when optimising the insulation structure of valve-side winding of the converter *** on the finite element multi-physical field coupling simulation,the multi-objective optimisation of main insulation structure of valve-side winding is carried *** view of the high time consuming of multi-physical field calculation and the actual needs of an insulation structure optimisation,the Kriging method and technique for order preference by similarity to the ideal solution(TOPSIS)method are introduced,and combines them with NSGA-II to obtain a joint algorithm that can be used for the optimisation of insulation structure of the converter *** using the joint algorithm of multi-objective optimisation,the insulation structure configuration scheme of valve-side winding is *** can be seen from the experiment result that,on the one hand,the joint algorithm adopted can obtain the insulation structure configuration scheme that meets the design *** the other hand,when facing the configuration scheme optimisation under multi-field coupling,the computational time required by this method is only 0.15%of that required by original genetic algorithm.

关键词： converter insulation coupling

Development of Mixed Insulation Oil as Alternative Liquid Dielectric:A Review

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CSEE Journal of power and Energy Systems 2024年第3期10卷 1242-1258页

作者： Jian Hao Jingwen Zhang Wenyu Ye Ruijing Liao Lijun Yang state key laboratory of power transmission equipment technology School of Electrical EngineeringChongqing UniversityChongqing 400044China IEEE CSEE

Use of traditional mineral oil(MO)as a liquid insulation in transformers has spanned more than 130 ***,MO has poor heat resistance,a low ignition point,and is a non-renewable resource,which does not meet development requirements for high-performance and environmentally friendly insulation ***,researchers have explored alternatives such as natural ester(NE)and synthetic ester(SE)oils,as well as mixed insulation *** insulating oil is a blend of diverse insulating oil types,with optimal performance achieved by adjusting proportions of base *** article summarizes the innovative achievements and development of mixed insulation oil in terms of development of mixed ratio,basic physical chemical properties,electrical properties,thermal stability,and application including operation and maintenance *** these efforts,this article aims to provide recommendations for future development of mixed insulating oils to advance liquid dielectric research based on enhancement mechanisms.

关键词： Environmentally friendly insulation oil ester oils high-performance mineral oil mixed insulation oils

Dynamic Constraint-Driven Event-Triggered Control of Strict-Feedback Systems Without Max/Min Values on Irregular Constraints

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 569-580页

作者： Zhuwu Shao Yujuan Wang Zeqiang Li Yongduan Song the state key laboratory of power transmission equipment&System Security and New technology and the School of AutomationChongqing UniversityChongqing 400044China IEEE

This work proposes an event-triggered adaptive control approach for a class of uncertain nonlinear systems under irregular *** the constraints considered in most existing papers,here the external irregular constraints are considered and a constraints switching mechanism(CSM)is introduced to circumvent the difficulties arising from irregular output *** on the CSM,a new class of generalized barrier functions are constructed,which allows the control results to be independent of the maximum and minimum values(MMVs)of constraints and thus extends the existing ***,we proposed a novel dynamic constraint-driven event-triggered strategy(DCDETS),under which the stress on signal transmission is reduced greatly and no constraints are violated by making a dynamic trade-off among system state,external constraints,and inter-execution *** is proved that the system output is driven to close to the reference trajectory and the semi-global stability is guaranteed under the proposed control scheme,regardless of the external irregular output *** also verifies the effectiveness and benefits of the proposed method.

关键词： Adaptive control dynamic constraint-driven event-triggered control irregular output constraints nonlinear strict-feed-back systems

Security-constrained transmission Maintenance Optimization Considering Generation and Operational Risk Costs

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Journal of Modern power Systems and Clean Energy 2024年第3期12卷 767-781页

作者： Dan Xu Zhi Cai Qian Cheng Guodong Huang Jingyang Zhou Junjie Tang Beijing key laboratory of Research and System Evaluation of power Dispatching Automation technology China Electric Power Research InstituteBeijing 100192China state key laboratory of power transmission equipment&System Security and New technology Chongqing UniversityChongqing 400044China

With the large-scale integration of renewable energy,the traditional maintenance arrangement during the load valley period cannot satisfy the transmission demand of renewable energy ***,in a market-oriented operation mode,the power dispatching control center aims to reduce the overall power purchase cost while ensuring the security of the power ***,a security-constrained transmission maintenance optimization model considering generation and operational risk costs is proposed *** model is built on double-layer optimization framework,where the upper-layer model is used for maintenance and generation planning,and the lowerlayer model is primarily used to address the operational security risk arising from the random prediction error and N-1 transmission ***,a generation-maintenance iterative algorithm based on a defined cost feedback is included to increase solution *** cost is determined using long-term security-constrained unit commitment,and the operational risk cost is obtained using a double-layer N-1 risk assessment *** electrical correlation coupling coefficient is proposed for the solution process to avoid maintenance of associated equipment simultaneously,thereby improving model convergence *** IEEE 118-bus system is used as a test case for illustration,and test results suggest that the proposed model and algorithm can reduce the total cost of transmission maintenance and system operation while effectively improving the solution efficiency of the joint optimization model.

关键词： transmission maintenance security-constrained unit commitment iterative algorithm cost feedback N−1 risk assessment

Multi-area Frequency-constrained Unit Commitment for power Systems with High Penetration of Renewable Energy Sources and Induction Machine Load

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Journal of Modern power Systems and Clean Energy 2024年第3期12卷 754-766页

作者： Leibao Wang Hui Fan Jifeng Liang Longxun Xu Tiecheng Li Peng Luo Bo Hu Kaigui Xie the state Grid Hebei Electric power Research Institute Shijiazhuang 050021China state key laboratory of power transmission equipment&System Security and New technology Chongqing UniversityChongqing 400044China

The increasing penetration of renewable energy sources(RESs)brings great challenges to the frequency security of power *** traditional frequency-constrained unit commitment(FCUC)analyzes frequency by simplifying the average system frequency and ignoring numerous induction machines(IMs)in load,which may underestimate the risk and increase the operational *** this paper,we consider a multiarea frequency response(MAFR)model to capture the frequency dynamics in the unit scheduling problem,in which regional frequency security and the inertia of IM load are modeled with high-dimension differential algebraic equations.A multi-area FCUC(MFCUC)is formulated as mixed-integer nonlinear programming(MINLP)on the basis of the MAFR ***,we develop a multi-direction decomposition algorithm to solve the MFCUC *** original MINLP is decomposed into a master problem and *** subproblems check the nonlinear frequency dynamics and generate linear optimization cuts for the master problem to improve the frequency security in its optimal *** studies on the modified IEEE 39-bus system and IEEE 118-bus system show a great reduction in operational ***,simulation results verify the ability of the proposed MAFR model to reflect regional frequency security and the available inertia of IMs in unit scheduling.

关键词： Decomposition algorithm frequency response frequency-constrained unit commitment induction machine multi-area mixed-integer nonlinear programming(MINLP)

Influence characteristics of water penetration on fibre-reinforced polymer/rigid polyurethane foam interface of the composite cross-arm considering natural ageing

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High Voltage 2024年第1期9卷 81-93页

作者： Jun Xie Zhe Zhou Ziqian Liu Haonan Tian Sigang Zhang Qing Xie Hebei Provincial key laboratory of power transmission equipment Security Defense North China Electric Power UniversityBaodingChina state Grid Gansu Electric power Company LanzhouChina

Fibre-reinforced polymer(FRP)/rigid polyurethane foam(RPUF)interface is susceptible to moisture intrusion in addition to natural ageing during *** study investigated the influence of moisture intrusion on the FRP/RPUF interface under natural ageing using experiments and molecular dynamics(MD)*** absorption,shear strength,and leakage current tests were used to clarify the changes in the interface *** degradation mechanism of moisture intrusion at the interface under natural ageing was revealed by MD simulation and *** results show that the natural ageing of interfacial materials will slightly reduce the quality of the interface but will reduce the water resistance of the material and promote the process of water intrusion into the *** addition,water mainly invades the interface through *** water penetration,the interfacial bonding strength and insulation performance significantly *** and hydrolysis of interfacial materials are the main reasons for decreased interfacial *** can cause irreversible damage to the interface,increasing interface defects and water *** vicious cycle of material hydrolysis is the ultimate cause of interfacial *** polar molecules produced by this process and the water absorbed by the interface caused the degradation of the interface insulation performance.

关键词： interface polyurethane interfacial

Study on the dynamic mechanical properties of winding-block axial structure considering short circuit strain rate effect

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High Voltage 2024年第2期9卷 380-390页

作者： Xinyu Wang Ping Wang Jianghai Geng Zikang Zhang Fangcheng Lü Shuguo Gao Hebei Provincial key laboratory of power transmission equipment Security Defense North China Electric Power UniversityBaodingChina state Grid Hebei Electric power Research Institute ShijiazhuangChina

Transformers may suffer multiple short-circuit impacts during long-term operation,and axial instability is one of the typical types of serious accidents caused by short-circuit *** axial instability form of the winding-block structure is analysed,and the dynamic solution of the winding short-circuit electromagnetic force is obtained by estab-lishing the three-dimensional magnetic-circuit-force multi-physical field coupling simulation *** influence of strain rate on the cushion block constitutive equation is corrected,and the modified model is verified by short-circuit impact test and quasi-static *** research results show that for 110 kV 31.5 MVA transformers,the maximum electromagnetic axial resultant force of winding is 363.16 kN,and the ultimate tilt force is 1214.2 *** pre-tightening force configuration is accordingly recom-mended to range from 363.16 to 608.28 kN,which is narrowed by 18.49%compared with the static calculation method;Meanwhile,adding a logarithmic strain rate correction term to the classical constitutive equation of the cushion block can achieve a good correction of the stress-strain relationship with the coefficient of determination above 0.99,and the cushion block has a larger elastic modulus under high strain rate *** research results provide an important theoretical reference for the axial stability structure of transformers.

关键词： axial correction structure

Low-power soft transistors triggering revolutionary electronics

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The Innovation 2024年第3期5卷 21-22页

作者： Ziyang Liu Yaoshen Zhao Zhigang Yin state key laboratory of power transmission equipment technology School of Electrical EngineeringChongqing UniversityChongqing 400044China

Transistors have been reshaping our lives since their initial appearance in the *** the central element of logic gates and integrated circuits(chips),they undoubtedly play an incomparable role in promoting the development of computers,smartphones,flat panel displays,Internet of Things,and even all electronic or electrical *** past decades have witnessed dominant transistors usually made from inorganic semiconductors such as silicon materials and metal oxides,which are advantageous to achieve high mobility,fast switching speed,and excellent ***,silicon transistors and metal oxide semiconductor field-effect transistors have been broadly used for electronic ***,these transistors are rigid and nearly approaching the fundamental limits on speed and power consumption,despite being manufactured at a much smaller scale to meet the projection of Moore’s *** future transistors with mechanical flexibility/robustness and low-power consumption are demanded,innovation in functional materials,device configurations,and integrated processing techniques to facilitate the evolution from rigid devices to soft,durable,and biocompatible devices is imperative.

关键词： approaching evolutionary doubt

Novel sandwich structured glass fiber Cloth/Poly(ethylene oxide)-MXene composite electrolyte

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Nano Materials Science 2024年第1期6卷 60-67页

作者： Yu-Qin Mao Guang-He Dong Wei-Bin Zhu Yuan-Qing Li Pei Huang Shao-Yun Fu College of Aerospace Engineering Chongqing UniversityChongqing400044China state key laboratory of power transmission equipment and System Security and New technology Chongqing UniversityChongqing400044China

Recently,poly(ethylene oxide)(PEO)-based solid polymer electrolytes have been attracting great attention,and efforts are currently underway to develop PEO-based composite electrolytes for next generation high performance all-solid-state lithium metal *** this article,a novel sandwich structured solid-state PEO composite electrolyte is developed for high performance all-solid-state lithium metal *** PEO-based composite electrolyte is fabricated by hot-pressing PEO,LiTFSI and Ti_(3)C_(2)T_(x) MXene nanosheets into glass fiber cloth(GFC).The as-prepared GFC@PEO-MXene electrolyte shows high mechanical properties,good electrochemical stability,and high lithium-ion migration number,which indicates an obvious synergistic effect from the microscale GFC and the nanoscale *** as,the GFC@PEO-1 wt%MXene electrolyte shows a high tensile strength of 43.43 MPa and an impressive Young's modulus of 496 MPa,which are increased by 1205%and 6048%over those of ***,the ionic conductivity of GFC@PEO-1 wt%MXene at 60℃ reaches 5.01×10^(-2) S m^(-1),which is increased by around 200%compared with that of GFC@PEO *** addition,the Li/Li symmetric battery based on GFC@PEO-1 wt%MXene electrolyte shows an excellent cycling stability over 800 h(0.3 mA cm^(-2),0.3 mAh cm^(-2)),which is obviously longer than that based on PEO and GFC@PEO electrolytes due to the better compatibility of GFC@PEO-1 wt%MXene electrolyte with Li ***,the solid-state Li/LiFePO_(4) battery with GFC@PEO-1 wt%MXene as electrolyte demonstrates a high capacity of 110.2–166.1 mAh g^(-1) in a wide temperature range of 25–60C,and an excellent capacity retention *** developed sandwich structured GFC@PEO-1 wt%MXene electrolyte with the excellent overall performance is promising for next generation high performance all-solid-state lithium metal batteries.

关键词： Solid polymer electrolyte Ti_(3)C_(2)T_(x)MXene Poly(ethylene oxide) Glass fiber cloth All-solid-state Li metal Battery

Analysis of SF6 decomposed products by fibre-enhanced Raman spectroscopy for gas-insulated switchgear diagnosis

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High Voltage 2024年第1期9卷 206-216页

作者： Jianxin Wang Weigen Chen Pinyi Wang Fu Wan Zhixian Zhang Shoufei Gao Yingying Wang School of Electrical Engineering Chongqing UniversityChongqingChina state key laboratory of power transmission equipment&System Security and New technology Chongqing UniversityChongqingChina Institute of Photonics technology Jinan UniversityGuangzhouChina

Sulphur hexafluoride(SF6)decomposed products analysis is highly critical in the earlystage fault diagnosis of gas-insulated switchgear(GIS).Spectrum technology outperforms traditional methods on non-invasiveness,no sample preparation,and no ***,the authors present an improved fibre-enhanced Raman spectroscopy(FERS)as a comprehensive analytical tool to detect a suite of SF_(6)decomposed products(SO_(2)F_(2),SOF_(2),SO_(2),H_(2)S,CF_(4),OCS,CO_(2),and CO).The FERS approach is combined with two iris diaphragms for spatial filtering and a rear-end reflector for additional Raman signal *** of detection down to 1×10^(−6)–8×10^(−6)are achieved for different SF6 decompositions,and quantification of an undefined multigas,sampled from an 800 kV GIS in service,is realised utilising SF6 as the internal standard gas and with a maximum error of 5.5%.The GIS is diagnosed according to the results and confirmed by an on-site *** authors foresee that this technique will provide a route for trace gas analysis in the power industry.

关键词： SF6 diagnosis fibre