The rapid development of the Network makes the comprehensive analysis as well as the quantitative evaluation of its security become more and mere important. This paper illustrates the major realization process of a Ne...The rapid development of the Network makes the comprehensive analysis as well as the quantitative evaluation of its security become more and mere important. This paper illustrates the major realization process of a Network Security Quantitative Evaluation System,which,from an intruder's angle ,established a Hierarchy Intrusion Relationship Graph by analyzing the credit degree fusion and relevancy of the secure information of the target network and by combining with powerful database information. At last, by applying some relative mathematics model and arithmetic, the paper analyzes and evaluates the security of this Network Hierarchy Intrusion Relationship Graph comprehensively and quantitatively.展开更多
A number of contingencies simulated during dynamic security assessment do not generate unacceptable values of power system state variables, due to their small influence on system operation. Their exclusion from the se...A number of contingencies simulated during dynamic security assessment do not generate unacceptable values of power system state variables, due to their small influence on system operation. Their exclusion from the set of contingencies to be simulated in the security assessment would achieve a significant reduction in computation time. This paper defines a critical contingencies selection method for on-line dynamic security assessment. The selection method results from an off-line dynamical analysis, which covers typical scenarios and also covers various related aspects like frequency, voltage, and angle analyses among others. Indexes measured over these typical scenarios are used to train neural networks, capable of performing on-line estimation of a critical contingencies list according to the system state.展开更多
The security evaluation for an information network system is an important management tool to insure its normal operation. We must realize the significance of the comprehensive network security risks. A network evaluat...The security evaluation for an information network system is an important management tool to insure its normal operation. We must realize the significance of the comprehensive network security risks. A network evaluation model and the algorithm are presented and adapt the hierarchical method to characterize the security risk situation. The evaluation method is used to evaluate the key nodes and the mathematics is used to analyze the whole network security situation. Compared with others, the method can automatically create a rule-based security evaluation model to evaluate the security threat from the individual security elements and the combination of security elements, and then evaluation the network situation. It is shown that this system provides a valuable model and algorithms to help to find the security rules, adjust the security展开更多
In this paper, online security warning and risk assessment of power grid are proposed, based on data from EMS （Energy Management System）, combined with information of real-time operation state, component status and ...In this paper, online security warning and risk assessment of power grid are proposed, based on data from EMS （Energy Management System）, combined with information of real-time operation state, component status and external operating environment. It combines the two factors, contingency likelihood and severity, that determine system reliability, into risk indices on different loads and operation modes, which provide precise evaluation of the power grid＇s security performance. According to these indices, it can know the vulnerable area of the system and whether the normal operating mode or repair mode is over-limited or not, and provide decision-making support for dispatchers. Common cause outages and equipment-aging are considered in terms of the establishment of outage model. Multiple risk indices are defined in order to reflect the risk level of the power grid more comprehensively.展开更多
文摘The rapid development of the Network makes the comprehensive analysis as well as the quantitative evaluation of its security become more and mere important. This paper illustrates the major realization process of a Network Security Quantitative Evaluation System,which,from an intruder's angle ,established a Hierarchy Intrusion Relationship Graph by analyzing the credit degree fusion and relevancy of the secure information of the target network and by combining with powerful database information. At last, by applying some relative mathematics model and arithmetic, the paper analyzes and evaluates the security of this Network Hierarchy Intrusion Relationship Graph comprehensively and quantitatively.
文摘A number of contingencies simulated during dynamic security assessment do not generate unacceptable values of power system state variables, due to their small influence on system operation. Their exclusion from the set of contingencies to be simulated in the security assessment would achieve a significant reduction in computation time. This paper defines a critical contingencies selection method for on-line dynamic security assessment. The selection method results from an off-line dynamical analysis, which covers typical scenarios and also covers various related aspects like frequency, voltage, and angle analyses among others. Indexes measured over these typical scenarios are used to train neural networks, capable of performing on-line estimation of a critical contingencies list according to the system state.
文摘The security evaluation for an information network system is an important management tool to insure its normal operation. We must realize the significance of the comprehensive network security risks. A network evaluation model and the algorithm are presented and adapt the hierarchical method to characterize the security risk situation. The evaluation method is used to evaluate the key nodes and the mathematics is used to analyze the whole network security situation. Compared with others, the method can automatically create a rule-based security evaluation model to evaluate the security threat from the individual security elements and the combination of security elements, and then evaluation the network situation. It is shown that this system provides a valuable model and algorithms to help to find the security rules, adjust the security
文摘In this paper, online security warning and risk assessment of power grid are proposed, based on data from EMS （Energy Management System）, combined with information of real-time operation state, component status and external operating environment. It combines the two factors, contingency likelihood and severity, that determine system reliability, into risk indices on different loads and operation modes, which provide precise evaluation of the power grid＇s security performance. According to these indices, it can know the vulnerable area of the system and whether the normal operating mode or repair mode is over-limited or not, and provide decision-making support for dispatchers. Common cause outages and equipment-aging are considered in terms of the establishment of outage model. Multiple risk indices are defined in order to reflect the risk level of the power grid more comprehensively.
