双馈风电场通过串联补偿装置进行远距离输电时存在发生次同步相互作用(sub-synchronous interactions,SSI)的风险。结合我国华北地区某风电场的实际情况,在PSCAD/EMTDC平台上搭建了用于研究SSI的双馈风电场的电磁暂态模型,利用PSCAD/EM...双馈风电场通过串联补偿装置进行远距离输电时存在发生次同步相互作用(sub-synchronous interactions,SSI)的风险。结合我国华北地区某风电场的实际情况,在PSCAD/EMTDC平台上搭建了用于研究SSI的双馈风电场的电磁暂态模型,利用PSCAD/EMTDC模型的特殊设置,实现系统机电以及控制特性的分离仿真研究,结合Prony分析法分析了串补电容、变流器控制、风机传动链对系统SSI的影响。然后研究了次同步作用回路的特性,提出了通过在转子侧变流器控制(rotor side control,RSC)中加入滤波器来抑制SSI的变流器控制改进方案以及滤波器的设计方法,最后通过仿真验证了方案的实用性和通用性。展开更多
This paper presents a model of cascading failures in cyber-physical power systems(CPPSs) based on an improved percolation theory, and then proposes failure mitigation strategies. In this model, the dynamic development...This paper presents a model of cascading failures in cyber-physical power systems(CPPSs) based on an improved percolation theory, and then proposes failure mitigation strategies. In this model, the dynamic development of cascading failures is divided into several iteration stages. The power flow in the power grid, along with the data transmission and delay in the cyber layer, is considered in the improved percolation theory. The interaction mechanism between two layers is interpreted as the observability and controllability analysis and data update analysis influencing the node state transformation and security command execution. The resilience indices of the failures reflect the influence of cascading failures on both topological integrity and operational state. The efficacy of the proposed mitigation strategies is validated, including strategies to convert some cyber layer nodes into autonomous nodes and embed unified power flow controller(UPFC) into the physical layer. The results obtained from simulations of cascading failures in a CPPS with increasing initial failure sizes are compared for various scenarios.Dynamic cascading failures can be separated into rapid and slow processes. The interdependencies and gap between the observable and controllable parts of the physical layer with the actual physical network are two fundamental reasons for first-order transition failures. Due to the complexity of the coupled topological and operational relations between the two layers, mitigation strategies should be simultaneously applied in both layers.展开更多
文摘双馈风电场通过串联补偿装置进行远距离输电时存在发生次同步相互作用(sub-synchronous interactions,SSI)的风险。结合我国华北地区某风电场的实际情况,在PSCAD/EMTDC平台上搭建了用于研究SSI的双馈风电场的电磁暂态模型,利用PSCAD/EMTDC模型的特殊设置,实现系统机电以及控制特性的分离仿真研究,结合Prony分析法分析了串补电容、变流器控制、风机传动链对系统SSI的影响。然后研究了次同步作用回路的特性,提出了通过在转子侧变流器控制(rotor side control,RSC)中加入滤波器来抑制SSI的变流器控制改进方案以及滤波器的设计方法,最后通过仿真验证了方案的实用性和通用性。
基金supported by the National Natural Science Foundation of China(No.51537010)the National Key Basic Research Program(973 Program)(No.2013CB228206)the project of ‘‘The up layer design for DC-AC hybrid grids system protection’’(No.XT71-16-053)
文摘This paper presents a model of cascading failures in cyber-physical power systems(CPPSs) based on an improved percolation theory, and then proposes failure mitigation strategies. In this model, the dynamic development of cascading failures is divided into several iteration stages. The power flow in the power grid, along with the data transmission and delay in the cyber layer, is considered in the improved percolation theory. The interaction mechanism between two layers is interpreted as the observability and controllability analysis and data update analysis influencing the node state transformation and security command execution. The resilience indices of the failures reflect the influence of cascading failures on both topological integrity and operational state. The efficacy of the proposed mitigation strategies is validated, including strategies to convert some cyber layer nodes into autonomous nodes and embed unified power flow controller(UPFC) into the physical layer. The results obtained from simulations of cascading failures in a CPPS with increasing initial failure sizes are compared for various scenarios.Dynamic cascading failures can be separated into rapid and slow processes. The interdependencies and gap between the observable and controllable parts of the physical layer with the actual physical network are two fundamental reasons for first-order transition failures. Due to the complexity of the coupled topological and operational relations between the two layers, mitigation strategies should be simultaneously applied in both layers.
