Survivability is the capability of a system to fulfill its mission in the presence of attacks, failures, or accidents, and recover full service in a timely manner. On the basis of J. K. Millen＇s survivability measure...Survivability is the capability of a system to fulfill its mission in the presence of attacks, failures, or accidents, and recover full service in a timely manner. On the basis of J. K. Millen＇s survivability measure method, the paper sets the PST-based （processing-storage-transmission） survivability system model, gives description of survivability of PST-based survivability systematic model, and proposes the algorithm of PST-based system survivability measure. Finally, it composes a system based on processing, storage and transmission, and gets the data of system survivability measure with the algorithm. It proves that the feasibility and validity of the method of PST-based system survivability measure.展开更多
The fracture behavior and mechanism of PST crystals of a Ti 49%(mole fraction)Al alloy have been studied by using in situ straining and micromechanical calculation. The three dimensional micromechanical model represen...The fracture behavior and mechanism of PST crystals of a Ti 49%(mole fraction)Al alloy have been studied by using in situ straining and micromechanical calculation. The three dimensional micromechanical model representing the structure of PST crystal has been built, and the stress distribution ahead of the sharp and blunt crack tips either parallel to lamellar interface or perpendicular to the lamellae has been calculated by using finite element method based on linear elasticity of PST crystals. The experimental results show that the fracture behaviors and mechanisms are strongly dependent on the angle of loading axis to the lamellae. The calculation indicates that nucleation and propagation of microcrack along the interfaces are controlled by the normal stress and translamellar microcrack is controlled by shear stress ahead of crack tip.展开更多
The aim of this work is to demonstrate that interphase power regulators (I</span></span><span style="white-space:normal;"><span style="font-family:"">PR) bring new...The aim of this work is to demonstrate that interphase power regulators (I</span></span><span style="white-space:normal;"><span style="font-family:"">PR) bring new and interesting ultra-solutions that complement those already taken into account by the FACTS (Flexible Alternative Transmission System) in the resolution of the problems related to the power flow in the AC transmission networks. In order to facilitate the understanding of this work, a comparative study of the performances of the two technologies between the UPFC (Unified Power Flow Controller) and RPI was carried out and at the end of which we were able to highlight the preponderance of RPI compared to the UPFC in the bypassing of the short-circuit fault insofar as the latter allows, in particular, an increase in the transformation capacity without an increase in the level of the short-circuit. The decoupled watt-var method has been used to control the UPFC while the RPI is controlled by phase shift. The simulation results are obtained in the Matlab Simulink environment and show the flexibility of the RPI compared to the UPFC in limiting strong contingencies.展开更多
基金Supported by Specialized Research Fund for Doctoral Program of Higher Education of China(20050217007)
文摘Survivability is the capability of a system to fulfill its mission in the presence of attacks, failures, or accidents, and recover full service in a timely manner. On the basis of J. K. Millen＇s survivability measure method, the paper sets the PST-based （processing-storage-transmission） survivability system model, gives description of survivability of PST-based survivability systematic model, and proposes the algorithm of PST-based system survivability measure. Finally, it composes a system based on processing, storage and transmission, and gets the data of system survivability measure with the algorithm. It proves that the feasibility and validity of the method of PST-based system survivability measure.
文摘The fracture behavior and mechanism of PST crystals of a Ti 49%(mole fraction)Al alloy have been studied by using in situ straining and micromechanical calculation. The three dimensional micromechanical model representing the structure of PST crystal has been built, and the stress distribution ahead of the sharp and blunt crack tips either parallel to lamellar interface or perpendicular to the lamellae has been calculated by using finite element method based on linear elasticity of PST crystals. The experimental results show that the fracture behaviors and mechanisms are strongly dependent on the angle of loading axis to the lamellae. The calculation indicates that nucleation and propagation of microcrack along the interfaces are controlled by the normal stress and translamellar microcrack is controlled by shear stress ahead of crack tip.
文摘The aim of this work is to demonstrate that interphase power regulators (I</span></span><span style="white-space:normal;"><span style="font-family:"">PR) bring new and interesting ultra-solutions that complement those already taken into account by the FACTS (Flexible Alternative Transmission System) in the resolution of the problems related to the power flow in the AC transmission networks. In order to facilitate the understanding of this work, a comparative study of the performances of the two technologies between the UPFC (Unified Power Flow Controller) and RPI was carried out and at the end of which we were able to highlight the preponderance of RPI compared to the UPFC in the bypassing of the short-circuit fault insofar as the latter allows, in particular, an increase in the transformation capacity without an increase in the level of the short-circuit. The decoupled watt-var method has been used to control the UPFC while the RPI is controlled by phase shift. The simulation results are obtained in the Matlab Simulink environment and show the flexibility of the RPI compared to the UPFC in limiting strong contingencies.
