含大规模分布式光伏与柔性负荷的新型配电网运行方式愈发复杂,配电网同步测量装置(synchrophasor measurement unit for distribution network,D-PMU)优化配置可为其协同调度控制提供有效的同步测量数据。然而,在配电网发生N-1故障并进...含大规模分布式光伏与柔性负荷的新型配电网运行方式愈发复杂,配电网同步测量装置(synchrophasor measurement unit for distribution network,D-PMU)优化配置可为其协同调度控制提供有效的同步测量数据。然而,在配电网发生N-1故障并进行重构后,原有的配置方案难以满足调度控制需求。因此,提出一种考虑N-1故障重构下的D-PMU优化配置方法。首先,提出计及配电网重构的节点电压损失和网络拓扑结构的节点脆弱程度指标,划分节点权重;为保证故障重构后配电网可观,提出考虑N-1故障重构的D-PMU优化配置模型,基于配电网重构获取了网络拓扑结构,建立N-1故障重构下的可观测约束,并考虑D-PMU通道数量有限以及数据监控与采集系统(supervisory control and data acquisition,SCADA)和高级量测系统(advanced measurement infrastructure,AMI)量测信息对所提模型的影响;建立D-PMU统一优化配置模型,充分考虑经济性、正常情况下的全网可观、零注入节点、N-1故障重构可观、D-PMU通道的限制和已存在的传统量测;进一步,利用IEEE 33和IEEE 69节点系统验证该方法的可行性和有效性。展开更多
On the basis of complex network theory, the issues of key nodes in Wireless Sensor Networks (WSN) are discussed. A model expression of sub-network fault in WSN is given at first; subsequently, the concepts of average ...On the basis of complex network theory, the issues of key nodes in Wireless Sensor Networks (WSN) are discussed. A model expression of sub-network fault in WSN is given at first; subsequently, the concepts of average path length and clustering coefficient are introduced. Based on the two concepts, a novel attribute description of key nodes related to sub-networks is proposed. Moreover, in terms of node deployment density and transmission range, the concept of single-point key nodes and generalized key nodes of WSN are defined, and their decision theorems are investigated.展开更多
The PBFT (Practical Byzantine Fault Tolerance, PBFT) consensus algorithm, which addressed the issue of malicious nodes sending error messages to disrupt the system operation in distributed systems, was challenging to ...The PBFT (Practical Byzantine Fault Tolerance, PBFT) consensus algorithm, which addressed the issue of malicious nodes sending error messages to disrupt the system operation in distributed systems, was challenging to support massive network nodes, the common participation over all nodes in the consensus mechanism would lead to increased communication complexity, and the arbitrary selection of master nodes would also lead to inefficient consensus. This paper offered a PBFT consensus method (Role Division-based Practical Byzantine Fault Tolerance, RD-PBFT) to address the above problems based on node role division. First, the nodes in the system voted with each other to divide the high reputation group and low reputation group, and determined the starting reputation value of the nodes. Then, the mobile node in the group was divided into roles according to the high reputation value, and a total of three roles were divided into consensus node, backup node, and supervisory node to reduce the number of nodes involved in the consensus process and reduced the complexity of communication. In addition, an adaptive method was used to select the master nodes in the consensus process, and an integer value was introduced to ensure the unpredictability and equality of the master node selection. Experimentally, it was verified that the algorithm has lower communication complexity and better decentralization characteristics compared with the PBFT consensus algorithm, which improved the efficiency of consensus.展开更多
针对区块链边缘节点的部署环境开放、安全措施薄弱、易受到安全攻击,以及计算和网络资源不足等问题,提出一种基于可信执行环境(TEE)的区块链安全架构P-Dledger。该架构通过构建两阶段的信任链,在满足软件便捷迭代的基础上,确保加载部件...针对区块链边缘节点的部署环境开放、安全措施薄弱、易受到安全攻击,以及计算和网络资源不足等问题,提出一种基于可信执行环境(TEE)的区块链安全架构P-Dledger。该架构通过构建两阶段的信任链,在满足软件便捷迭代的基础上,确保加载部件的可信;通过实现智能合约可信执行框架以及基于串行外设接口或非门存储器(SPI NOR Flash)的数据可信存储,保证智能合约的可信计算与数据的可信存储;同时,为共识提案赋予单调递增的唯一标识,限制拜占庭节点的行为。实验与分析结果表明:所提架构确保了加载主体、账本数据与执行过程的安全可信;当网络延时大于60 ms或节点数大于8时,P-Dledger比采用拜占庭容错(PBFT)算法的区块链系统的吞吐量更高,且随着网络延时与节点数的增加,P-Dledger性能表现更稳定。展开更多
摘要含大规模分布式光伏与柔性负荷的新型配电网运行方式愈发复杂,配电网同步测量装置(synchrophasor measurement unit for distribution network,D-PMU)优化配置可为其协同调度控制提供有效的同步测量数据。然而,在配电网发生N-1故障并进行重构后,原有的配置方案难以满足调度控制需求。因此,提出一种考虑N-1故障重构下的D-PMU优化配置方法。首先,提出计及配电网重构的节点电压损失和网络拓扑结构的节点脆弱程度指标,划分节点权重;为保证故障重构后配电网可观,提出考虑N-1故障重构的D-PMU优化配置模型,基于配电网重构获取了网络拓扑结构,建立N-1故障重构下的可观测约束,并考虑D-PMU通道数量有限以及数据监控与采集系统(supervisory control and data acquisition,SCADA)和高级量测系统(advanced measurement infrastructure,AMI)量测信息对所提模型的影响;建立D-PMU统一优化配置模型,充分考虑经济性、正常情况下的全网可观、零注入节点、N-1故障重构可观、D-PMU通道的限制和已存在的传统量测;进一步,利用IEEE 33和IEEE 69节点系统验证该方法的可行性和有效性。
基金Supported by the National High Technology Research and Development Program of China(No.2008AA01A201)the National Natural Science Foundation of China(No.60503015)
摘要On the basis of complex network theory, the issues of key nodes in Wireless Sensor Networks (WSN) are discussed. A model expression of sub-network fault in WSN is given at first; subsequently, the concepts of average path length and clustering coefficient are introduced. Based on the two concepts, a novel attribute description of key nodes related to sub-networks is proposed. Moreover, in terms of node deployment density and transmission range, the concept of single-point key nodes and generalized key nodes of WSN are defined, and their decision theorems are investigated.
摘要The PBFT (Practical Byzantine Fault Tolerance, PBFT) consensus algorithm, which addressed the issue of malicious nodes sending error messages to disrupt the system operation in distributed systems, was challenging to support massive network nodes, the common participation over all nodes in the consensus mechanism would lead to increased communication complexity, and the arbitrary selection of master nodes would also lead to inefficient consensus. This paper offered a PBFT consensus method (Role Division-based Practical Byzantine Fault Tolerance, RD-PBFT) to address the above problems based on node role division. First, the nodes in the system voted with each other to divide the high reputation group and low reputation group, and determined the starting reputation value of the nodes. Then, the mobile node in the group was divided into roles according to the high reputation value, and a total of three roles were divided into consensus node, backup node, and supervisory node to reduce the number of nodes involved in the consensus process and reduced the complexity of communication. In addition, an adaptive method was used to select the master nodes in the consensus process, and an integer value was introduced to ensure the unpredictability and equality of the master node selection. Experimentally, it was verified that the algorithm has lower communication complexity and better decentralization characteristics compared with the PBFT consensus algorithm, which improved the efficiency of consensus.
摘要针对区块链边缘节点的部署环境开放、安全措施薄弱、易受到安全攻击,以及计算和网络资源不足等问题,提出一种基于可信执行环境(TEE)的区块链安全架构P-Dledger。该架构通过构建两阶段的信任链,在满足软件便捷迭代的基础上,确保加载部件的可信;通过实现智能合约可信执行框架以及基于串行外设接口或非门存储器(SPI NOR Flash)的数据可信存储,保证智能合约的可信计算与数据的可信存储;同时,为共识提案赋予单调递增的唯一标识,限制拜占庭节点的行为。实验与分析结果表明:所提架构确保了加载主体、账本数据与执行过程的安全可信;当网络延时大于60 ms或节点数大于8时,P-Dledger比采用拜占庭容错(PBFT)算法的区块链系统的吞吐量更高,且随着网络延时与节点数的增加,P-Dledger性能表现更稳定。