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广东电网变电站接地网安全性状态评估 被引量:17
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作者 李谦 肖磊石 饶章权 《南方电网技术》 2013年第5期21-26,共6页
南方电网变电站接地网预防性试验的重点已从单纯定期接地阻抗测量转到以必要时开展接地网安全性状态评估为主的模式。针对接地网状态评估这个全新的试验项目,在总结广东电网近年来变电站接地网状态评估工作的基础上,探讨了开展接地网状... 南方电网变电站接地网预防性试验的重点已从单纯定期接地阻抗测量转到以必要时开展接地网安全性状态评估为主的模式。针对接地网状态评估这个全新的试验项目,在总结广东电网近年来变电站接地网状态评估工作的基础上,探讨了开展接地网状态评估的技术路线以及接地分析软件的数值分析作用,对所归纳的接地网安全性状态方面存在的问题,提出了解决方案和对策。 展开更多
关键词 变电站 接地网 安全性状态评价 数值分析
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500kV香山变电站接地网安全性状态评估及整改 被引量:7
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作者 李谦 杨劲松 《广东电力》 2013年第5期87-92,共6页
针对变电站发生接地短路故障时,设备场区电位差和接触电压偏高的问题,基于现场实际测量和接地分析软件CDEGS(current distribution,electromagnetic field,grounding and soil structure analysis)数值计算,对500kV香山变电站接地网安... 针对变电站发生接地短路故障时,设备场区电位差和接触电压偏高的问题,基于现场实际测量和接地分析软件CDEGS(current distribution,electromagnetic field,grounding and soil structure analysis)数值计算,对500kV香山变电站接地网安全性状态进行评估。通过仿真计算,提出在高接触电压值的区域采用加密水平接地网格,在高接触电压值场的区地面铺设高阻砾石或高阻层,设备外壳喷涂高阻层等整改措施。实施整改措施后,变电站运行情况表明整改工程达到了提高接地网安全性的目的。 展开更多
关键词 接地分析软件 数值仿真 接地网 安全性状态评估 接触电压
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基于CDEGS变电站大型接地网安全性状态诊断及分析 被引量:7
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作者 余炜 余云光 +3 位作者 王允光 腾飞 赵元东 何磊 《电力设备管理》 2021年第4期67-69,共3页
针对某220 kV变电站的接地网安全性诊断及分析,提出接地网安全问题的解决方案,改变以往接地网只单一检测接地阻抗的方式,提高接地网安全运行水平。
关键词 大型接地网 安全性状态 CDEGS仿真
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使用困难报告数据驱动的民用航空器安全状态评价 被引量:2
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作者 杨晓强 林湘漪 蒋澜 《中国安全科学学报》 CAS CSCD 北大核心 2021年第11期85-92,共8页
为识别民用航空器的安全状态,提出一种基于使用困难报告(SDR)数据的民用航空器安全性状态评价方法。分析A320机型的SDR数据,按照民用航空器系统/部件通用代码分类标准建立航空器安全性状态评价指标体系,并利用指标相关性赋权(CRITIC)法... 为识别民用航空器的安全状态,提出一种基于使用困难报告(SDR)数据的民用航空器安全性状态评价方法。分析A320机型的SDR数据,按照民用航空器系统/部件通用代码分类标准建立航空器安全性状态评价指标体系,并利用指标相关性赋权(CRITIC)法得到各指标权重;应用指标模糊分割模型和全乘比例分析多目标优化方法(MULTIMOORA)构建航空器安全性状态评价模型,并将该模型运用于实例分析。研究结果表明:SDR的发生次数大体上服从正态分布,可确定安全性状态划分标准;优势理论可对比率模型、参照点法、全乘模型的结果综合排序;最终得到的A320机型的安全性状态整体处于中等水平,这一结果与实际情况基本吻合。 展开更多
关键词 使用困难报告(SDR) 民用航空器 安全性状态 指标模糊分割模型 全乘比例分析多目标优化方法(MULTIMOORA)
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土壤特性对变电站接地网特性参数影响的数值分析 被引量:43
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作者 李谦 文习山 肖磊石 《高电压技术》 EI CAS CSCD 北大核心 2013年第11期2656-2663,共8页
为了了解土壤特性对接地网特性参数(接地阻抗、地线分流、地网电位升高、场区压差、跨步电压和接触电压)的影响规律,结合具体的工程案例,采用数值仿真方法,分析接地网特性参数与土壤分层结构特性之间的相关性。结果表明,站址土壤电阻率... 为了了解土壤特性对接地网特性参数(接地阻抗、地线分流、地网电位升高、场区压差、跨步电压和接触电压)的影响规律,结合具体的工程案例,采用数值仿真方法,分析接地网特性参数与土壤分层结构特性之间的相关性。结果表明,站址土壤电阻率不同时,接地网特性参数在变电站发生单相接地短路故障时具有不同的表现行为,接地网特性参数是分层结构土壤电阻率、接地网结构和形状以及入地故障电流水平等几个因素协同作用的结果。高土壤电阻率条件不利于散流,地网电位升高较高,但整体压差较小,跨步电压和接触电压分布较为均衡。低分层土壤电阻率条件下,地网电位升高很低,但场区压差较大,高水平跨步电压和接触电压可能出现在接地故障点且超过安全限值,在设计时应注意均压措施的完善。 展开更多
关键词 土壤特性 接地网 特性参数 设计 安全性状态评价 分层
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Modeling for Action of Recovering from Erroneous Driving Condition Based on Revised Decision Tree 被引量:1
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作者 王武宏 沈中杰 杜秋 《Journal of Beijing Institute of Technology》 EI CAS 2002年第1期61-65,共5页
Driving behavior modeling is very important in the research area of road traffic systems safety analysis. The characteristics of action of recovering from erroneous driving condition underlying road traffic accident o... Driving behavior modeling is very important in the research area of road traffic systems safety analysis. The characteristics of action of recovering from erroneous driving condition underlying road traffic accident or incident scenarios is quantitatively analyzed, the model of action of recovering from erroneous driving condition is set up according to the identification of erroneous driving condition and the measurement of correction from erroneous driving condition. And then, the probability of action of recovering from erroneous driving condition has been measured based on a revised decision tree. The measure process uses a combination of test data and subjective judgments of driving behavior. It can provide a very helpful theoretical basis for the further analysis of driving behavior in road traffic system. 展开更多
关键词 road traffic safety driving reliability action of recovering from erroneous driving condition
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Quantum Distributed Ballot Scheme Based on Greenberger-Horne-Zeilinger State 被引量:1
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作者 施荣华 伍莹 +1 位作者 郭迎 曾贵华 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第8期257-262,共6页
Motivated by the complementary relations of the Greenberger-Horne-Zeilinger (GHZ) entangled tripletparticlestates,a novel way of realizing quantum distributed ballot scheme is proposed.The ballot information is encode... Motivated by the complementary relations of the Greenberger-Horne-Zeilinger (GHZ) entangled tripletparticlestates,a novel way of realizing quantum distributed ballot scheme is proposed.The ballot information is encodedby local operations performed on the particles of entangled GHZ triplet states,which ensures the security of the presentscheme.In order to guarantee the security of this scheme,the checking phase is designed in detail on the basis of theentangled GHZ triplet state.The analysis shows the security of the proposed scheme. 展开更多
关键词 quantum distributed ballot scheme Greenberger-Horne-Zeilinger state
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Two-Step Efficient Deterministic Secure Quantum Communication Using Three-Qubit W State
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作者 袁好 周军 +2 位作者 张刚 魏相飞 刘向远 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第6期984-988,共5页
A two-step deterministic secure quantum communication (DSQC) scheme using blocks of three-qubit W state is proposed. In this scheme, the secret messages can be encoded by employing four two-particle unitary operatio... A two-step deterministic secure quantum communication (DSQC) scheme using blocks of three-qubit W state is proposed. In this scheme, the secret messages can be encoded by employing four two-particle unitary operations and directly decoded by utilizing the corresponding measurements in Bell basis or single-particle basis. Comparing with most previous DSQC protocols, the present scheme has a high total efficiency, which comes up to 50%. Apart from this, it has still the advantages of high capacity as each W state can carry two bits of secret information, and high intrinsic efficiency because almost all the instances are useful. Furthermore, the security of this communication can be ensured by the decoy particle checking technique and the two-step transmitting idea. 展开更多
关键词 deterministic secret quantum communication three-qubit W states decoy particle checking technique two-step transmitting idea
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Chaotic synchronization based on nonlinear state-observer and its application in secure communication
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作者 CHENMing-jie LIDian-pu ZHANGAi-jun 《Journal of Marine Science and Application》 2004年第1期64-70,共7页
Chaotic synchronization is a branch of chaotic control. Nowadays, the research and application of chaotic synchronization have become a hot topic and one of the development directions is for the research on chaos. In ... Chaotic synchronization is a branch of chaotic control. Nowadays, the research and application of chaotic synchronization have become a hot topic and one of the development directions is for the research on chaos. In this paper, a universal nonlinear stateobserver is presented for a class of universal chaotic systems to realize the chaotic synchronization, according to the theory of state-observer in the modern control theory. And theoretic analysis and simulation results have illustrated the validity of the approach. Moreover, the approach of synchronization proposed in this paper is very easy, flexible and universal with high synchronization precision.When the approach is applied to secure communication, the results are satisfying. 展开更多
关键词 chaotic synchronization nonlinear stoLe-observer synchronization error secure communication
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Functional safety verification and performance measurement of train-train communication link
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作者 LIN Junting XU Qian CHEN Yong 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2021年第4期463-471,共9页
The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2... The short-range wireless communication technology has advanced considerably and provides the feasibility of train-train(T2T)communication link in the communication-based train control system.The introduction of the T2T link would reduce the headway and improve operational efficiency.Formal methods are system design techniques that use rigorously specified mathematical models to ensure all behaviors work as expected.And it is exactly the functional safety verification needed.Therefore,to deal with the functional safety verification of the T2T link,an untimed colored petri net model is first constructed.Secondly,the verification process is performed.Conclusions can be drawn from the state space report and the computation tree logic queries.Lastly,the model is parameterized,and then data log files are obtained for further performance measurement.Results show that the proposed criteria are satisfied and there are no defects in the basic design requirements.The transmission delay has considered the reconnection,transmission errors and the interruption.The probability of the delay lower than 150 ms accounts for 98.106%,which meets the specification and the previous field test. 展开更多
关键词 functional safety formal methods colored Petri net(CPN) state space analysis performance measurement
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Seismic Safety of RC Framed Buildings Designed According to Modern Codes
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作者 Juan Carlos Vielma Barbat Alex Oiler Sergio 《Journal of Civil Engineering and Architecture》 2011年第7期567-575,共9页
In order to ensure that a structure does not collapse when subjected to the action of strong ground motions, modern codes include prescriptions in order to guarantee the ductile behavior of the elements and of the who... In order to ensure that a structure does not collapse when subjected to the action of strong ground motions, modern codes include prescriptions in order to guarantee the ductile behavior of the elements and of the whole structure. Obviously, it would be of special importance for the designer to know during the design process the extent of damage that the structure will suffer under the seismic action specified by the design spectrum and also the probability of occurrence of different states of behavior. The incremental nonlinear static analysis procedure used in this paper allows formulating a new, simplified, seismic damage index and damage thresholds associated with five limit states. The seismic behavior of a set of regular reinforced concrete buildings designed according to the EC-2/EC-8 prescriptions for a high seismic hazard level is then studied using the proposed damage index and damage states. Fragility curves and damage probability matrices corresponding to the performance point are calculated for the studied buildings. The obtained results show that the collapse damage state is not reached in the buildings designed according to the prescriptions of EC-2/EC-8 and also that the damage does not exceed the irreparable damage limit state. 展开更多
关键词 Non linear analysis limit states OVERSTRENGTH DUCTILITY redundancy.
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Quality Characteristics and Microbiology Status in Kundi, an Intermediate Moisture Meat (IMM) Product
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作者 Patience Olusola Fakolade 《Journal of Agricultural Science and Technology(B)》 2012年第7期841-847,共7页
Meat and meat products are extremely perishable, so special care and handling must be exercised during slaughtering operation. Moreover, due to its high nutritive value, deterioration set in immediately after slaughte... Meat and meat products are extremely perishable, so special care and handling must be exercised during slaughtering operation. Moreover, due to its high nutritive value, deterioration set in immediately after slaughtered, therefore it is necessary to preserved meat, using simple techniques. One of such method of preservation is drying method to produced Intermediate Moisture Meat (IMM). The quality attributes and microbiological status of Kundi, a West African dried meat product (IMM) were studied over three months of storage period by comparing commercial products and laboratory Kundi products. Chemical and minerals composition and microbiological counts were reported. Moisture and water activity results indicated that the experimental Kundi was sufficiently dried to minimize microbial growth. Fat oxidation levels measured by free fatty acids (FFA, %) on extracted fats were unacceptably high for the commercial Kundi (2.64%), which may be a reflection of the oil used in spraying the products. Processing of Kundi, appears to have relative higher amounts of minerals than fresh meat but their relative solubility were lower. Aflatoxin levels far exceeded established safe limits for commercial samples while laboratory samples fell under the safe limits, resulting from the mould growth in each product, with laboratory samples having lower growth than commercial samples. 展开更多
关键词 Camel meat BEEF FUNGI mold and qualities characteristics.
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Power Uprate and Lifetime Extension
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作者 P. Schimann Z. Stosic 《Journal of Energy and Power Engineering》 2011年第9期834-841,共8页
Overall purpose of a power uprate and lifetime extension project (PLEX) is to modernize the power station cost-efficiently resulting in fulfilling the following overall requirements. The primary target is to meet th... Overall purpose of a power uprate and lifetime extension project (PLEX) is to modernize the power station cost-efficiently resulting in fulfilling the following overall requirements. The primary target is to meet the requirements provided by the local regulations from the regulatory offices. The controlling, monitoring and power supply of safety functions have to comply with these regulations. Any deviations from the existing safety analysis report (SAR) have to be corrected. On top of the safety measures the general technical status should be raised to extend the lifetime to 60 years. A high availability during the modernization has to be assured. 展开更多
关键词 Power uprate PLEX LICENSING lifetime extension PSA reactor protection system IAEA NPP.
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