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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 operation.This study investigated the influence of moisture intrusion on the FRP/RPUF interface under natural ageing using experiments and molecular dynamics(MD)simulations.Water absorption,shear strength,and leakage current tests were used to clarify the changes in the interface performance.The degradation mechanism of moisture intrusion at the interface under natural ageing was revealed by MD simulation and micro-characterisation.The 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 interface.In addition,water mainly invades the interface through RPUF.After water penetration,the interfacial bonding strength and insulation performance significantly decreased.Plasticisation and hydrolysis of interfacial materials are the main reasons for decreased interfacial adhesion.Hydrolysis can cause irreversible damage to the interface,increasing interface defects and water absorption.The vicious cycle of material hydrolysis is the ultimate cause of interfacial debonding.The 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

Adaptive Learning-Based Delay-Sensitive and Secure Edge-End Collaboration for Multi-Mode Low-Carbon power IoT

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China Communications 2022年第7期19卷 324-336页

作者： Haijun Liao Zehan Jia Ruiqiuyu Wang Zhenyu Zhou Fei Wang Dongsheng Han Guangyuan Xu Zhenti Wang Yan Qin hebei Key Laboratory of power Internet of Things Technology North China Electric Power UniversityBaoding 071003HebeiChina state grid Anhui electric power company Chuzhou power Supply company Chuzhou 239000AnhuiChina

Multi-mode power internet of things(PIoT)combines various communication media to provide spatio-temporal coverage for low-carbon operation in smart park.Edge-end collaboration is feasible to achieve the full utilization of heterogeneous resources and anti-eavesdropping.However,edge-end collaboration-based multi-mode PIoT faces challenges of mutual contradiction in communication and security quality of service(QoS)guarantee,inadaptability of resource management,and multi-mode access conflict.We propose an Adaptive learning based delAysensitive and seCure Edge-End Collaboration algorithm(ACE_(2))to optimize multi-mode channel selection and split device power into artificial noise(AN)transmission and data transmission for secure data delivery.ACE_(2) can achieve multi-attribute QoS guarantee,adaptive resource management and security enhancement,and access conflict elimination with the combined power of deep actor-critic(DAC),“win or learn fast(WoLF)”mechanism,and edge-end collaboration.Simulations demonstrate its superior performance in queuing delay,energy consumption,secrecy capacity,and adaptability to differentiated low-carbon services.

关键词： multi-mode low-carbon PIoT edge-end collaboration multi-attribute QoS guarantee security enhancement adaptive deep actor-critic

An Efficient Method for Identifying the Inactive Transmission Constraints in a Network-Constrained Unit Commitment

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CSEE Journal of power and Energy Systems 2023年第6期9卷 2366-2373页

作者： Ziming Ma Haiwang Zhong Qing Xia Chongqing Kang Qiang Wang Xin Cao the state Key Laboratory of power Systems and the Department of electrical Engineering Tsinghua UniversityBeijing 100084China State Grid Hebei Electric Power Company Shijiazhuang 050000China

Network-constrained unit commitment(NCUC)is one of the most widely used applications in power system and electricity market operations.According to empirical evidence,some of the transmission constraints in a NCUC are inactive.Identifying and eliminating these inactive constraints can improve the efficiency.In this paper,an efficient method is first proposed for identifying the inactive transmission constraints.The physical and economic insights of NCUC are carefully considered and utilized.Both the generating costs and power transfer distribution factor(PTDF)are considered.Not only redundant constraints but also non-binding constraints can be identified via the proposed method.An acceleration method that combines relaxation-based neighborhood search and improved relaxation inducement is proposed for further reducing the computation time.The case study shows that the proposed method can significantly reduce the number of transmission constraints and substantially improve the efficiency of NCUC without impacting the optimality.

关键词： Inactive transmission constraints improved relaxation inducement(IRI) network-constrained unit commitment(NCUC) relaxation-based neighborhood search(RBNS)

A Design of 220 kV Line Protection Action Deduction System Based on Numerical Simulation

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Energy Engineering 2022年第5期119卷 2105-2134页

作者： Tiecheng Li Qingquan Liu Hui Fan Xianzhi Wang Daming Zhou Junan Guo Lee Li Kun Zhou Yujie Hu state grid hebei electrical power company Research Institute Shijiazhuang050021China state grid hebei electrical power company Shijiazhuang050021China Wuhan Kemov electric Co. Ltd.Wuhan430223China

Accurate conditions monitoring and early wrong action warnings of relay protection in the Smart Substation is the basic guarantee to realize the normal operation of primary and secondary system of the power grid.At present,the traditional operation and maintenance monitoring methods of relay protections have poor timeliness,while some automatic monitoring methods have insufficient early warning performance,and lack the online action deduction function independent of the actual device.In this paper,a design method of integrated action deduction system including protection logic reasoning and software and hardware operation condition is proposed.The system can receive real-time operation information of protection online,simulate different types of faults,and output the recording information of sub modules belongs to the action deduction system.It can realize the online monitoring of device faults such as deducing the correctness of setting values at a certain time in the future,giving the wrong action warnings and predicting the probability of them as well,which effectively improves the operation and maintenance efficiency of the secondary system in the intelligent substation.

关键词： Intelligent substation numerical simulation relay protection conditions monitoring wrong action warning

Distribution Network Equipment Location and Capacity Planning Method Considering Energy Internet Attribute from the Perspective of Life Cycle Cost

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Energy Engineering 2022年第3期119卷 1059-1074页

作者： Qiang Li Lei Xue Xia Lin state grid Shanxi electric power company Economic and Technical Research Institute TaiyuanChina state grid Shanxi electric power company TaiyuanChina

For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribution network equipment and capacity from the perspective of life cycle cost.Compared with the traditional energy network,the equipment capacity problem of energy interconnected distribution network which involves in electricity network,thermal energy network and natural gas network is comprehensively considered in this paper.On this basis,firstly,the operation architecture of energy interconnected distribution network is designed.Secondly,taking the grid connection location and configuration capacity of key equipment in the system as the control variables and the operation cost of system comprehensive planning in the whole life cycle as the goal,the equipment location and capacity optimization model of energy interconnected distribution network is established.Finally,an IEEE 33 bus energy mutual distribution grid system is taken for example analysis,and the improved chaotic particle swarmoptimization algorithm is used to solve it.The simulation results show that the method proposed in this paper is suitable for the equipment location and capacity planning of energy interconnected distribution network,and it can effectively improve the social and economic benefits of system operation.

关键词： Locating and sizing method distribution energy internetwork whole life cycle cost distribution network planning

Operating system network security enhancement scheme based on trusted storage

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Intelligent and Converged Networks 2023年第2期4卷 127-141页

作者： Longyun Qi Xiaoliang Lv Lianwen Sun Tianle Yao Jianye Yu Lei Wang state grid electric power Research Institute Nanjing 210003China state grid Beijing electric power company Beijing 100031China

Data storage security has become the core of many network security issues.In order to achieve trusted storage and trusted measurement of network community data,this paper proposes a secure storage model based on trust extension for existing trusted storage technologies.In the process of document encryption,the key information is encrypted as well as decentralized stored by optimizing the ciphertext inverted index structure and update policy to ensure the security of index information.In the process of user access control mechanism,SAML and XACML are used in combination with role-based access control in order to achieve flexible and efficient authorization and access control.In the process of result query,ontology technology is introduced to better express the user’s query intention and improve the query accuracy.A large number of experiments demonstrate the effectiveness and feasibility of the scheme.

关键词： trusted storage trust extension trusted platform model(TPM) access control

The influences of silane coupling agents on the heat and moisture resistance of basalt fibre-reinforced composites

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High Voltage 2023年第1期8卷 38-47页

作者： Yunpeng Liu Mingjia Zhang Hechen Liu Yu Sun Wanxian Wang Jie Liu hebei Provincial Key Laboratory of power Transmission Equipment Security Defence North China Electric Power UniversityBaodingChina state Key Laboratory of Alternate electrical power System with Renewable Energy Sources North China Electric Power UniversityBaodingChina State Grid Hebei Electric Power Company electric power Research Institute ShijiazhuangChina

Basalt fibre composite materials have shown good application prospects in electrical equipment,but their reliability can be affected by damp-heat ageing.In this work,the interface,mechanical,and electrical properties of basalt fibre composites treated with three coupling agents via damp-heat ageing were compared.Molecular simulations were conducted to reveal the damp-heat ageing mechanism of the composites.The results show thatγ-aminopropyl triethoxy silane(KH-550)andγ-glycidoxy propyl trimethoxy silane(KH-560)perform better as coupling agents as they form bonds with the matrix resin,compared withγ-methacryloxy propyl trimethoxy silane(KH-570).After the dampheat ageing treatment,the hydrolysis of the defects of the amino groups in the interface of the KH-550-treated sample can weaken its mechanical properties and insulation properties greatly.The interface layer of the KH-560-treated sample is mostly composed of carbon–oxygen single bonds and methylene groups with its interface structure more stable,which endows the sample with better stability of its mechanical and insulating properties.Therefore,KH-560 is a more suitable coupling agent for processing basalt fibres to be used in electrical equipment.

关键词： composites coupling fibre

The feasibility of continuous basalt fibre-reinforced polymer application to composite cross-arms

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High Voltage 2023年第3期8卷 590-598页

作者： Yunpeng Liu Mingjia Zhang Hechen Liu Yunfan Ma Wanxian Wang Xiaohan Dai Jie Liu hebei Provincial Key Laboratory of power Transmission Equipment Security Defence North China Electric Power UniversityBaodingChina state Key Laboratory of Alternate electrical power System with Renewable Energy Sources North China Electric Power UniversityBaodingChina State Grid Hebei Electric Power Company electric power Research Institute ShijiazhuangChina

Composite cross-arms have the advantages of high lightning resistance but impose onerous requirements on mechanical and insulation reliability.Traditional glass fibre composites fail to meet the needs of practical applications.Basalt fibre exhibits better mechanical properties and stability than glass fibre and has potential application value.This study aims to evaluate the feasibility of its application to composite cross-arms.The mechanical,electrical,and physical properties of basalt fibre-reinforced polymer(BFRP)were investigated and compared with glass fibre-reinforced polymer(GFRP).The results indicate that BFRP has better thermal stability and mechanical properties than GFRP.Among them,the temperature at the maximum weight loss rate of BFRP is 14℃ higher than that of GFRP,and the tensile and flexural modulus of BFRP is 43%and 29%higher than those of GFRP.Furthermore,the dielectric losses of BFRP and GFRP at 50 Hz are 2%,and the breakdown field strength is 22 kV/mm,both of which have the same insulation properties.BFRP meets the requirements of composite cross-arm for quality and reliability to ensure the safety and stability of transmission lines.However,the interlaminar shear test and SEM show weak interfacial bonding strength between basalt fibre and resin.Furthermore,micro-computed tomography scanning of BFRP and GFRP and 3D construction of their internal microstructures indicate that the pore defect content of BFRP reaches 0.034%,which far exceeds that of GFRP.These findings show that the wettability and adhesion between basalt fibre and resin must be improved.Developing special sizing agents for basalt fibre is necessary further to improve the mechanical and electrical properties of BFRP.

关键词： fibre basalt composite

Trust Access Authentication in Vehicular Network Based on Blockchain

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China Communications 2019年第6期16卷 18-30页

作者： Shaoyong Guo Xing Hu Ziqiang Zhou Xinyan Wang Feng Qi Lifang Gao state Key Laboratory of Networking and Switching Technology BUPTBeijing 100876China state grid Zhejiang electric power Co. Ltd.Institute of Electric Power ScienceZhejiang 310007China state grid Henan electric power company Information and Communication company Henan 450052China State Grid Hebei Electric Power Company Information and Communication CompanyHebei 050022China

Data sharing and privacy securing present extensive opportunities and challenges in vehicular network.This paper introducestrust access authentication scheme’as a mechanism to achieve real-time monitoring and promote collaborative sharing for vehicles.Blockchain,which can provide secure authentication and protected privacy,is a crucial technology.However,traditional cloud computing performs poorly in supplying low-latency and fast-response services for moving vehicles.In this situation,edge computing enabled Blockchain network appeals to be a promising method,where moving vehicles can access storage or computing resource and get authenticated from Blockchain edge nodes directly.In this paper,a hierarchical architecture is proposed consist of vehicular network layer,Blockchain edge layer and Blockchain network layer.Through a authentication mechanism adopting digital signature algorithm,it achieves trusted authentication and ensures valid verification.Moreover,a caching scheme based on many-to-many matching is proposed to minimize average delivery delay of vehicles.Simulation results prove that the proposed caching scheme has a better performance than existing schemes based on central-ized model or edge caching strategy in terms of hit ratio and average delay.

关键词： blockchain vehicular network edge computing authentication mechanism many-to-many matching