基于准确而完整的SCADA／EMS(Supervisory Control and Data Acquisition／Energy Management System)系统数据库平台，电压无功优化控制软件从状态估计或调度员潮流信息获取基态数据，对电网电压进行监视。同时，根据分区调压原则，改...基于准确而完整的SCADA／EMS(Supervisory Control and Data Acquisition／Energy Management System)系统数据库平台，电压无功优化控制软件从状态估计或调度员潮流信息获取基态数据，对电网电压进行监视。同时，根据分区调压原则，改变无功补偿设备的位置、容量、运行状态，调节有载调压变压器的分接头挡位，提高电网的电压质量，降低系统因不必要的无功潮流引起的损耗，展开更多
By decoupling control plane and data plane,Software-Defined Networking(SDN) approach simplifies network management and speeds up network innovations.These benefits have led not only to prototypes,but also real SDN dep...By decoupling control plane and data plane,Software-Defined Networking(SDN) approach simplifies network management and speeds up network innovations.These benefits have led not only to prototypes,but also real SDN deployments.For wide-area SDN deployments,multiple controllers are often required,and the placement of these controllers becomes a particularly important task in the SDN context.This paper studies the problem of placing controllers in SDNs,so as to maximize the reliability of SDN control networks.We present a novel metric,called expected percentage of control path loss,to characterize the reliability of SDN control networks.We formulate the reliability-aware control placement problem,prove its NP-hardness,and examine several placement algorithms that can solve this problem.Through extensive simulations using real topologies,we show how the number of controllers and their placement influence the reliability of SDN control networks.Besides,we also found that,through strategic controller placement,the reliability of SDN control networks can be significantly improved without introducing unacceptable switch-to-controller latencies.展开更多
文摘基于准确而完整的SCADA／EMS(Supervisory Control and Data Acquisition／Energy Management System)系统数据库平台，电压无功优化控制软件从状态估计或调度员潮流信息获取基态数据，对电网电压进行监视。同时，根据分区调压原则，改变无功补偿设备的位置、容量、运行状态，调节有载调压变压器的分接头挡位，提高电网的电压质量，降低系统因不必要的无功潮流引起的损耗，
基金supported in part by the National High Technology Research and Development Program(863 Program)of China under Grant No.2011AA01A101the National High Technology Research and Development Program(863 Program)of China under Grant No.2013AA01330the National High Technology Research and Development Program(863 Program)of China under Grant No.2013AA013303
文摘By decoupling control plane and data plane,Software-Defined Networking(SDN) approach simplifies network management and speeds up network innovations.These benefits have led not only to prototypes,but also real SDN deployments.For wide-area SDN deployments,multiple controllers are often required,and the placement of these controllers becomes a particularly important task in the SDN context.This paper studies the problem of placing controllers in SDNs,so as to maximize the reliability of SDN control networks.We present a novel metric,called expected percentage of control path loss,to characterize the reliability of SDN control networks.We formulate the reliability-aware control placement problem,prove its NP-hardness,and examine several placement algorithms that can solve this problem.Through extensive simulations using real topologies,we show how the number of controllers and their placement influence the reliability of SDN control networks.Besides,we also found that,through strategic controller placement,the reliability of SDN control networks can be significantly improved without introducing unacceptable switch-to-controller latencies.
