Software rejuvenation is a recently proposed practive fault-tolerance approach to counteract software-aging phenomenon. Compared with clusters of a flat architecture, all the nodes share the same functions. The applic...Software rejuvenation is a recently proposed practive fault-tolerance approach to counteract software-aging phenomenon. Compared with clusters of a flat architecture, all the nodes share the same functions. The application of software rejuvenation on dispatcher-based web server farms is discussed, which employ rejuvenation both on the dispatcher and the worker pool. Stochastic reward net (SRN)models for time-based and prediction-based rejuvenation policies are constructed respectively and solved by stochastic Petri net package (SPNP). Numerical results show that appropriate rejuvenation strategies on the dispatcher and the worker pool could significantly reduce the expected downtime cost of the whole web server farm.展开更多
在电力调度的高峰时段,实时数据网络通信需求激增,同步数字体系(Synchronous Digital Hierarchy,SDH)架构带宽利用率低,出现传输瓶颈,无法满足网络传输的需求,影响电力调度实时性。因此,文章提出设计电力调度通信网络SDH传输架构。通过...在电力调度的高峰时段,实时数据网络通信需求激增,同步数字体系(Synchronous Digital Hierarchy,SDH)架构带宽利用率低,出现传输瓶颈,无法满足网络传输的需求,影响电力调度实时性。因此,文章提出设计电力调度通信网络SDH传输架构。通过优化后的电力调度通信网络设备,调整通信网络SDH拓扑结构,确定合适的节点位置,优化通信网络SDH传输通路组织。同时,加强网络电力调度通信安全防护。根据仿真测试结果,文章方法的信息传输平均速率为1.94 Mb/s,数据同步完成时间为8 s,证明通过优化设计,可以提高电力调度通信网络SDH传输架构的传输效率和电力系统的稳定性。展开更多
The operational environment of today's smart grids is becoming more complicated than ever before. A number of factors, including renewable penetration, marketization, cyber security, and hazards of nature, bring c...The operational environment of today's smart grids is becoming more complicated than ever before. A number of factors, including renewable penetration, marketization, cyber security, and hazards of nature, bring challenges and even threats to control centers. New techniques are anticipated to help dispatchers become aware of the accurate situations as they manipulate and navigate the situations as quickly as possible. To address the issues, we first introduce the background for this topic as well as the emerging technical demands of situational awareness in the dispatcher's environment. The general concepts and technical requirements of situational awareness are then summarized, aimed at offering an overview for readers to understand the state-of-the-art progress in this area. In addition, we discuss the importance of integrating the architecture of support tools in accordance with the dispatcher's thought process, which in fact guides correct and swift reactions in real-time operations. Finally, the prospects for situational awareness architecture are investigated with the goal of presenting situational awareness modules in an advanced and visualized manner.展开更多
针对多园区综合能源系统的分布式调度问题,文中构造了多园区综合能源系统的多主体架构,提出了一种分布式经济调度的基本框架,建立了多决策主体的集中式优化调度模型;利用交替方向乘子法(Alternating Direction Method of Multipliers,AD...针对多园区综合能源系统的分布式调度问题,文中构造了多园区综合能源系统的多主体架构,提出了一种分布式经济调度的基本框架,建立了多决策主体的集中式优化调度模型;利用交替方向乘子法(Alternating Direction Method of Multipliers,ADMM),引入功率协调变量解耦园区间互济功率,将集中式优化调度转换为具有一致性的各园区分散自治子优化问题;构建了基于ADMM分布式调度模型与算法,实现了与集中式优化调度几乎一致的优化结果,同时克服了集中式方法信息隐私安全性低、通信成本高、建模复杂、求解难度大等缺陷。最后,分别以简单和复杂的多园区综合能源系统为算例,验证了ADMM算法的计算性能及其相较于集中式方法的特点和优势。展开更多
文摘Software rejuvenation is a recently proposed practive fault-tolerance approach to counteract software-aging phenomenon. Compared with clusters of a flat architecture, all the nodes share the same functions. The application of software rejuvenation on dispatcher-based web server farms is discussed, which employ rejuvenation both on the dispatcher and the worker pool. Stochastic reward net (SRN)models for time-based and prediction-based rejuvenation policies are constructed respectively and solved by stochastic Petri net package (SPNP). Numerical results show that appropriate rejuvenation strategies on the dispatcher and the worker pool could significantly reduce the expected downtime cost of the whole web server farm.
文摘在电力调度的高峰时段,实时数据网络通信需求激增,同步数字体系(Synchronous Digital Hierarchy,SDH)架构带宽利用率低,出现传输瓶颈,无法满足网络传输的需求,影响电力调度实时性。因此,文章提出设计电力调度通信网络SDH传输架构。通过优化后的电力调度通信网络设备,调整通信网络SDH拓扑结构,确定合适的节点位置,优化通信网络SDH传输通路组织。同时,加强网络电力调度通信安全防护。根据仿真测试结果,文章方法的信息传输平均速率为1.94 Mb/s,数据同步完成时间为8 s,证明通过优化设计,可以提高电力调度通信网络SDH传输架构的传输效率和电力系统的稳定性。
基金the National Natural Science Foundation of China(No.51437003)
文摘The operational environment of today's smart grids is becoming more complicated than ever before. A number of factors, including renewable penetration, marketization, cyber security, and hazards of nature, bring challenges and even threats to control centers. New techniques are anticipated to help dispatchers become aware of the accurate situations as they manipulate and navigate the situations as quickly as possible. To address the issues, we first introduce the background for this topic as well as the emerging technical demands of situational awareness in the dispatcher's environment. The general concepts and technical requirements of situational awareness are then summarized, aimed at offering an overview for readers to understand the state-of-the-art progress in this area. In addition, we discuss the importance of integrating the architecture of support tools in accordance with the dispatcher's thought process, which in fact guides correct and swift reactions in real-time operations. Finally, the prospects for situational awareness architecture are investigated with the goal of presenting situational awareness modules in an advanced and visualized manner.
文摘针对多园区综合能源系统的分布式调度问题,文中构造了多园区综合能源系统的多主体架构,提出了一种分布式经济调度的基本框架,建立了多决策主体的集中式优化调度模型;利用交替方向乘子法(Alternating Direction Method of Multipliers,ADMM),引入功率协调变量解耦园区间互济功率,将集中式优化调度转换为具有一致性的各园区分散自治子优化问题;构建了基于ADMM分布式调度模型与算法,实现了与集中式优化调度几乎一致的优化结果,同时克服了集中式方法信息隐私安全性低、通信成本高、建模复杂、求解难度大等缺陷。最后,分别以简单和复杂的多园区综合能源系统为算例,验证了ADMM算法的计算性能及其相较于集中式方法的特点和优势。
