Study On The Impact Of Grid Structure On Blackout Risk

With growing demand for electricity in modern society, power grid develops to large-scale operation and complicated structure from initial small-scale and simple.China power grid has basically formed a nationwide interconnection, sending power from west to east, mutual supply between south and north. Scale-up of power network promotes the reasonable allocation of resources and the rapid development of national economy. At the same time, it greatly increases the risk of cascading failure caused by local accident. The occurrence of malignant cascading failure will cause incalculable economic losses and social influence, however, a reasonable power network structure is conducive to guarantee safe and stable operation of power grid, and reduce blackout risk. Therefore, study on the impact of grid structure on blackout risk is of great significance for guiding power grid planning,building strong network system,and defending power system safe and efficient operation.This thesis based on power system complexity theory, analyzes the relation between grid structure and blackout risk through power-law distribution of load loss,on the basis of power failure model proposed previously by the research group. First of all, power grid is transformed to the typical topologies. Power-law index which extracted from loss load data obtained by power failure simulation is used for measuring the risk of typical grid structures. Then according to the distribution characteristics between blackouts' scale and probability, piecewise power exponent is proposed to assess the risk of typical grid structures. The results verify the relation between grid structure and blackout risk. Finally, the power-law index and the piecewise power exponent, is applied to the analysis of actual SD power grid's blackout risk under the typical structures, and the feasibility and effectiveness of the indicators is verified.