The optimization process of embedded, or DG （distributed generation） is a very complex task, and it should be evaluated and compared by means of multi-criteria methods of analysis. The classical method for selection...The optimization process of embedded, or DG （distributed generation） is a very complex task, and it should be evaluated and compared by means of multi-criteria methods of analysis. The classical method for selection is usually based only on a single criterion analysis, and it is defined by thermal or economic aspects. The problem of optimal dispatch of DG is typical example of optimization, because it differs from the classical problem of generation dispatch in the power system, due to the specific criteria related to the DG interconnection. The most important goals are to maximize the renewable production and to minimize the total cost, while satisfying additional constraints related to the operation of a distribution network. As there are many DGs in a distribution network, it is very complicated to decide the optimal DG outputs to satisfy all the criteria and constraints imposed by the distribution network. Another problem is the lack of the dispatcher control over DGs, and very often, the only available action is to switch on or off the generator. Finally, network operator and DG owner perspective are often opposed regarding appropriate control action in the network. In this paper, a multicriteria decision support based on AHP （analytical hierarchical processes） method is proposed for the choice of the dispatching action. The method is illustrated on the choice of the DG to be switched off in the case or reverse power flow.展开更多
The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the resul...The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the results show that the epicenters are distributed in the near NS direction, the length of aftershock concentration zone is about 30kin, and the main shock is about 14km in depth. The depth of the sequence is distributed in the range of 0 -4km and 5 -20km, and the layer of 4 -5kin depth is an apparent earthquake absence layer. The cross-section along the fracture＇s long axis shows there is an irregular seismic gap in the middle segment of the aftershock region, which is the rupture region of 3 the M6 3/4earthquake in 1955, and this earthquake occurred in the south of the gap. We believe that the Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was a result of rupture of the residual asperity caused by the stress adjustment of the Wenchuan Ms8. 0 earthquake. The other two profiles perpendicular to the long axis show that the focal depth in the north segment is larger and the fault plane dips NW, which is consistent with the dip of the Hongge fault.展开更多
This paper proposes an agent-based distributed scheduling system against the background of the deregulation of electric utility and the smart grid for the renewable energy, and then focuses on a maintenance scheduling...This paper proposes an agent-based distributed scheduling system against the background of the deregulation of electric utility and the smart grid for the renewable energy, and then focuses on a maintenance scheduling in the context of real problems. A synchronous backtrack algorithm, a welD-known method for distributed scheduling problems, has difficulties handling （A） rapid schedule adjustments and （B） impartial assignment. Thus, this paper proposes two kinds of heuristics： （1） parallel assignment and （2） multiple priority strategies, and developed the distributed scheduling system which makes use of the heuristics. It consists of schedulers for each power station and mediation agents which have cloning and merging functions to support the implementation of the heuristics. Finally, the result of experiment shows an improvement when handling the rapid adjustment and the impartiality issues with reasonable computational overhead.展开更多
Using the Cluster data from 2001 to 2010, we studied spatial distribution of effective ion polytropic index in the southern high latitude magnetosheath, and joint-modulation of ion polytropic index by temperature anis...Using the Cluster data from 2001 to 2010, we studied spatial distribution of effective ion polytropic index in the southern high latitude magnetosheath, and joint-modulation of ion polytropic index by temperature anisotropy and MHD disturbances. The magnetosheath ions generally experience various polytropic processes with different polytropic index. The median polytropic indexes of magnetosheath ions in the GSE X-Y plane decrease toward the bow shock. Near the magnetopause, the median polytropic indexes are basically between isothermal and adiabatic except in the duskside flank close to the terminator. The analysis of correlation coefficient of perturbed ion number density with parallel magnetic field CC_δnδB_‖ and ion temperature anisotropy parameter A_T, indicates that the dominant MHD disturbance near magnetopause is slow mode with larger ion temperature anisotropy, and there are various modes of MHD disturbances with insignificant ion temperature anisotropy near the bow shock.The polytropic index modulated by slow mode disturbances is generally larger than that modulated by fast mode disturbances, and the larger ion temperature anisotropy, the larger polytropic index. The median polytropic indexes modulated jointly by slow mode disturbances and the strong ion temperature anisotropy can be larger than 1.0, while those modulated by fast mode disturbances and weak temperature anisotropy can be even possibly close to zero. Moreover, because of pronounced dusk-favored asymmetry of ion temperature anisotropy, the median polytropic index in the dawnside flank of the magnetosheath near the terminator is smaller than that in the duskside flank of the magnetosheath. The good correspondence between the distributions of median polytropic indexes and ion temperature anisotropy and MHD disturbances indicates that the ion temperature anisotropy and MHD disturbances determine the distribution of the polytropic index in the magnetosheath.展开更多
文摘The optimization process of embedded, or DG （distributed generation） is a very complex task, and it should be evaluated and compared by means of multi-criteria methods of analysis. The classical method for selection is usually based only on a single criterion analysis, and it is defined by thermal or economic aspects. The problem of optimal dispatch of DG is typical example of optimization, because it differs from the classical problem of generation dispatch in the power system, due to the specific criteria related to the DG interconnection. The most important goals are to maximize the renewable production and to minimize the total cost, while satisfying additional constraints related to the operation of a distribution network. As there are many DGs in a distribution network, it is very complicated to decide the optimal DG outputs to satisfy all the criteria and constraints imposed by the distribution network. Another problem is the lack of the dispatcher control over DGs, and very often, the only available action is to switch on or off the generator. Finally, network operator and DG owner perspective are often opposed regarding appropriate control action in the network. In this paper, a multicriteria decision support based on AHP （analytical hierarchical processes） method is proposed for the choice of the dispatching action. The method is illustrated on the choice of the DG to be switched off in the case or reverse power flow.
基金funded jointly by the National Natural Science Foundation of China(40674040,41074062)the scientific investigation project of the M_S 7.0 Lushan earthquakethe special program for seismic network backbones of CEA(20150422)
文摘The Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was relocated using the Hypo2000 ＋ HypoDD algorithm with the seismic phase data from the Sichuan and Yunnan regional digital seismic networks, and the results show that the epicenters are distributed in the near NS direction, the length of aftershock concentration zone is about 30kin, and the main shock is about 14km in depth. The depth of the sequence is distributed in the range of 0 -4km and 5 -20km, and the layer of 4 -5kin depth is an apparent earthquake absence layer. The cross-section along the fracture＇s long axis shows there is an irregular seismic gap in the middle segment of the aftershock region, which is the rupture region of 3 the M6 3/4earthquake in 1955, and this earthquake occurred in the south of the gap. We believe that the Panzhihua Ms6. 1 earthquake sequence on August 30, 2008 was a result of rupture of the residual asperity caused by the stress adjustment of the Wenchuan Ms8. 0 earthquake. The other two profiles perpendicular to the long axis show that the focal depth in the north segment is larger and the fault plane dips NW, which is consistent with the dip of the Hongge fault.
文摘This paper proposes an agent-based distributed scheduling system against the background of the deregulation of electric utility and the smart grid for the renewable energy, and then focuses on a maintenance scheduling in the context of real problems. A synchronous backtrack algorithm, a welD-known method for distributed scheduling problems, has difficulties handling （A） rapid schedule adjustments and （B） impartial assignment. Thus, this paper proposes two kinds of heuristics： （1） parallel assignment and （2） multiple priority strategies, and developed the distributed scheduling system which makes use of the heuristics. It consists of schedulers for each power station and mediation agents which have cloning and merging functions to support the implementation of the heuristics. Finally, the result of experiment shows an improvement when handling the rapid adjustment and the impartiality issues with reasonable computational overhead.
基金supported by the National Natural Science Foundation of China(Grant Nos.41431071,41504127,and 41474124)
文摘Using the Cluster data from 2001 to 2010, we studied spatial distribution of effective ion polytropic index in the southern high latitude magnetosheath, and joint-modulation of ion polytropic index by temperature anisotropy and MHD disturbances. The magnetosheath ions generally experience various polytropic processes with different polytropic index. The median polytropic indexes of magnetosheath ions in the GSE X-Y plane decrease toward the bow shock. Near the magnetopause, the median polytropic indexes are basically between isothermal and adiabatic except in the duskside flank close to the terminator. The analysis of correlation coefficient of perturbed ion number density with parallel magnetic field CC_δnδB_‖ and ion temperature anisotropy parameter A_T, indicates that the dominant MHD disturbance near magnetopause is slow mode with larger ion temperature anisotropy, and there are various modes of MHD disturbances with insignificant ion temperature anisotropy near the bow shock.The polytropic index modulated by slow mode disturbances is generally larger than that modulated by fast mode disturbances, and the larger ion temperature anisotropy, the larger polytropic index. The median polytropic indexes modulated jointly by slow mode disturbances and the strong ion temperature anisotropy can be larger than 1.0, while those modulated by fast mode disturbances and weak temperature anisotropy can be even possibly close to zero. Moreover, because of pronounced dusk-favored asymmetry of ion temperature anisotropy, the median polytropic index in the dawnside flank of the magnetosheath near the terminator is smaller than that in the duskside flank of the magnetosheath. The good correspondence between the distributions of median polytropic indexes and ion temperature anisotropy and MHD disturbances indicates that the ion temperature anisotropy and MHD disturbances determine the distribution of the polytropic index in the magnetosheath.
