Research On Cascading Failure Model In Power Grid And Its Control Straregy

The rapid development of the economy in China proposes an even more stringent requirement for the reliability of power supply. The rising of load results in that the overall security of the power grid is as well subjecting to a severe challenge. The fault in some part of th grid might spread to the nearby power grid, and induce a chain reaction. The out of operation of the components would be resulting in widespread power outages and even the collapse of the entire grid. Therefore, to prevent the occurrence and spread of cascading failure is the key to avoid large-scale blackout.First of all, by combing three civil and international large-scale power accidents caused by cascading failures, the evolution regularity of the cascading failure is summarized, and being arrived at the general pattern of grid accidents caused by the cascading faliure. Then from the perspective of line-cluster, the paper reveals the mechanism of cascading failure. In condition of the increasing complete of grid and higher line safety margin, Self-sustaining chain reaction is hard to happen in the modern grid in China, however, under the influence of the changing environment, the fault chance of grid is on an evident rise, causing enormous destructive effect on grid componets, dramatically increasing the relating and non-relating faults.In addition, based on the theory of self-organized criticality, starting from the relevant association between cascading failure and grid components as well as grid componets and their status, the complex grid failure propagating chain model, in consideration of adverse weather, is established, simulating the potential cascading failure trail during the process of evolution of grid self-organized status in form of failure propagating chain, converting the monitroing on cascading failures into the monitoring on the links of the failure propagating chain, thereby providing a theoretical basis for the prevention and control strategy of large-scale blackouts caused by cascading failure.In accordance with control timing, this paper then based on the analysis of general cascading failure evolution pattern, taking risk assessment and importance measure into account, proposes two kinds of control strategies. One is based on failure propagating chain risk assessment, used for precaution and prevention control in the period of initial stage of faults accumulation. The other one is based on the decision-making control of intermediate links in failure propagating chain, used for emergency control in the period of chain reaction stage. The above two strategies provides a practical measure for researching on the control method of cascading failures. In the end, by adopting the typical winter heavy load data of2010Northern Henan power grid, simulation proves the availability and feasibility of the model and the control methods.