Based on the analysis of inherent limitations in existing security response decision-making systems, a dynamic adaptive model of fault response is presented. Several security fault levels were founded, which comprise ...Based on the analysis of inherent limitations in existing security response decision-making systems, a dynamic adaptive model of fault response is presented. Several security fault levels were founded, which comprise the basic level, equipment level and mechanism level. Fault damage cost is calculated using the analytic hierarchy process. Meanwhile, the model evaluates the impact of different responses upon fault repair and normal operation. Response operation cost and response negative cost are introduced through quantitative calculation. This model adopts a comprehensive response decision of security fault in three principles--the maximum and minimum principle, timeliness principle, acquiescence principle, which assure optimal response counter- measure is selected for different situations. Experimental results show that the proposed model has good self- adaptation ability, timeliness and cost-sensitiveness.展开更多
The fault activation （fault on） interrupts the enduring fault locking （fault off） and marks the end of a seismic cycle in which the brittle-ductile transition （BDT） acts as a sort of switch. We suggest that the ...The fault activation （fault on） interrupts the enduring fault locking （fault off） and marks the end of a seismic cycle in which the brittle-ductile transition （BDT） acts as a sort of switch. We suggest that the fluid flow rates differ during the different periods of the seismic cycle （interseismic, pre-seismic, coseismic and post-seismic） and in particular as a function of the tectonic style. Regional examples indicate that tectonic-related fluids anomalies depend on the stage of the tectonic cycle and the tectonic style. Although it is difficult to model an increasing permeability with depth and several BDT transitions plus independent acquicludes may occur in the crust, we devised the simplest numerical model of a fault constantly shearing in the ductile deeper crust while being locked in the brittle shallow layer, with variable homogeneous permeabilities. The results indicate different behaviors in the three main tectonic settings. In tensional tectonics, a stretched band antithetic to the normal fault forms above the BDT during the interseismic period. Fractures close and fluids are expellecl during the coseismic stage. The mechanism reverses in compressional tectonics. During the interseismic stage, an over-compressed band forms above the BDT. The band dilates while rebounding in the coseismic stage and attracts fluids locally. At the tip lines along strike-slip faults, two couples of subvertical bancls show different behavior, one in dilationJcompression and one in compressionJdilation. This deformation pattern inverts during the coseismic stage. Sometimes a pre-seismic stage in which fluids start moving may be observed and could potentially become a precursor.展开更多
This paper investigates long-period ground motion characteristic of the 1999 Jiji （Chi-Chi）, Taiwan, mainshock and aftershocks on the basis of lots of high quality digital strong motion records. The study attaches t...This paper investigates long-period ground motion characteristic of the 1999 Jiji （Chi-Chi）, Taiwan, mainshock and aftershocks on the basis of lots of high quality digital strong motion records. The study attaches the importance to the variation of strength of the long-period ground motion with the magnitude, distance, and site condition. In the meantime, the near-fault long-period ground motion characteristic is analyzed. The result shows that the shape of the long-period response spectrum is mainly controlled by site condition and magnitude （the spectrum of class D＋E is wider than that of class B＋C, and the spectrum of larger magnitude is wider than that of smaller magni- tude）, and the effect of fault distance on the shape is not evident. And near-fault long-period ground motion characteristic depends on fault activity apparently, that is to say, the long-term ground motion in the hanger is stronger than that in the footwall, and the long-term ground motion in the north is stronger than that in the south.展开更多
Numerous renewable energy sources(RESs)are coupled with the power grid through power electronics to advance low-carbon objectives.These RESs predominantly connect to the AC collection network via inverters,with the el...Numerous renewable energy sources(RESs)are coupled with the power grid through power electronics to advance low-carbon objectives.These RESs predominantly connect to the AC collection network via inverters,with the electricity they produce either transmitted over long distances through high-voltage lines or utilized locally within the distribution system.The unique interfacing of RESs alters their fault response characteristics,typically resulting in limited fault currents,frequency deviations,and fluctuating sequence impedance angles.Therefore,existing protection principles based on fault signatures of synchronous generators will face significant challenges including distance relays,directional elements,differential relays,phase selectors,and overcurrent relays.To solve these issues,innovative protection technologies have been developed to bolster grid stability and security.Furthermore,the superior controllability of power converters presents an opportunity to devise effective control strategies that can adapt existing protection mechanisms to function correctly in this new energy landscape.Nevertheless,the complexity of fault behaviors exhibited by RESs necessitates further refinement of these schemes.Therefore,this paper aims to consolidate current research methodologies and explore prospective avenues for future investigation.展开更多
基金Sponsored by the Ministerial Level Foundation(20021823)
文摘Based on the analysis of inherent limitations in existing security response decision-making systems, a dynamic adaptive model of fault response is presented. Several security fault levels were founded, which comprise the basic level, equipment level and mechanism level. Fault damage cost is calculated using the analytic hierarchy process. Meanwhile, the model evaluates the impact of different responses upon fault repair and normal operation. Response operation cost and response negative cost are introduced through quantitative calculation. This model adopts a comprehensive response decision of security fault in three principles--the maximum and minimum principle, timeliness principle, acquiescence principle, which assure optimal response counter- measure is selected for different situations. Experimental results show that the proposed model has good self- adaptation ability, timeliness and cost-sensitiveness.
基金funding provided by the Italian Presidenza del Consiglio dei Ministri-Dipartimento della Protezione Civile (DPC) within the INGV-DPC 2007-2009 agreement (Project S1)Sapienza UniversityCNR-Eurocores-TopoEurope
文摘The fault activation （fault on） interrupts the enduring fault locking （fault off） and marks the end of a seismic cycle in which the brittle-ductile transition （BDT） acts as a sort of switch. We suggest that the fluid flow rates differ during the different periods of the seismic cycle （interseismic, pre-seismic, coseismic and post-seismic） and in particular as a function of the tectonic style. Regional examples indicate that tectonic-related fluids anomalies depend on the stage of the tectonic cycle and the tectonic style. Although it is difficult to model an increasing permeability with depth and several BDT transitions plus independent acquicludes may occur in the crust, we devised the simplest numerical model of a fault constantly shearing in the ductile deeper crust while being locked in the brittle shallow layer, with variable homogeneous permeabilities. The results indicate different behaviors in the three main tectonic settings. In tensional tectonics, a stretched band antithetic to the normal fault forms above the BDT during the interseismic period. Fractures close and fluids are expellecl during the coseismic stage. The mechanism reverses in compressional tectonics. During the interseismic stage, an over-compressed band forms above the BDT. The band dilates while rebounding in the coseismic stage and attracts fluids locally. At the tip lines along strike-slip faults, two couples of subvertical bancls show different behavior, one in dilationJcompression and one in compressionJdilation. This deformation pattern inverts during the coseismic stage. Sometimes a pre-seismic stage in which fluids start moving may be observed and could potentially become a precursor.
基金National Natural Science Foundation of China (50278090).
文摘This paper investigates long-period ground motion characteristic of the 1999 Jiji （Chi-Chi）, Taiwan, mainshock and aftershocks on the basis of lots of high quality digital strong motion records. The study attaches the importance to the variation of strength of the long-period ground motion with the magnitude, distance, and site condition. In the meantime, the near-fault long-period ground motion characteristic is analyzed. The result shows that the shape of the long-period response spectrum is mainly controlled by site condition and magnitude （the spectrum of class D＋E is wider than that of class B＋C, and the spectrum of larger magnitude is wider than that of smaller magni- tude）, and the effect of fault distance on the shape is not evident. And near-fault long-period ground motion characteristic depends on fault activity apparently, that is to say, the long-term ground motion in the hanger is stronger than that in the footwall, and the long-term ground motion in the north is stronger than that in the south.
基金carried out with the European Union’s Horizon ResearchInnovation Programme under Marie Sklodowska-Curie Grant Agreement(No.101145934)UKRI Postdoctoral Fellowships Guarantee(No.EP/Z002168/1).
文摘Numerous renewable energy sources(RESs)are coupled with the power grid through power electronics to advance low-carbon objectives.These RESs predominantly connect to the AC collection network via inverters,with the electricity they produce either transmitted over long distances through high-voltage lines or utilized locally within the distribution system.The unique interfacing of RESs alters their fault response characteristics,typically resulting in limited fault currents,frequency deviations,and fluctuating sequence impedance angles.Therefore,existing protection principles based on fault signatures of synchronous generators will face significant challenges including distance relays,directional elements,differential relays,phase selectors,and overcurrent relays.To solve these issues,innovative protection technologies have been developed to bolster grid stability and security.Furthermore,the superior controllability of power converters presents an opportunity to devise effective control strategies that can adapt existing protection mechanisms to function correctly in this new energy landscape.Nevertheless,the complexity of fault behaviors exhibited by RESs necessitates further refinement of these schemes.Therefore,this paper aims to consolidate current research methodologies and explore prospective avenues for future investigation.
